331/347 stroker with cam swap

[EarlyWormEatsTheBird]

Hey guys, I am currently running a stock bottom end 302 with GT40P heads, longtube headers, Edelbrock performer rpm intake, trickflow stage one cam, scorpion 1.6 ratio roller rockers, and an fi tech throttle body fuel injection system on my 85 hatch. I'd like to start fresh with a full engine rebuild, and am considering stroking my 302 out to either a 331 or 347 since I am going to have to have my cylinders bored anyway. I intend on upgrading my heads later on and figure since I wanna pull the engine anyway, might as well go ahead and stroke it to even further reap the benefits of some nice AFRs later down the line. I'm aware doing heads at the same time as the rebuild would be ideal, but I do not mind doing it later, plus, it would allow time for saving up for the heads, while scratching my itch at the same time lol. My question is this, if I do this rebuild with a stroker kit while keeping my GT40P heads and swapping my cam to something with more duration to take advantage of the increased stroke, how much do I stand to gain from this? As stated previously, I'm going to upgrade the heads later anyway so in the long run I know it will be worth it. Has anyone else run a stroker setup with GT40Ps? If so how did it run?

[Jerry peachuer]

If you run those heads consider running aftermarket valves as 1 option
Not necessarily needed but will help more flow without touching ports

REV makes nice valve which are back cut and this makes them not only lighter but reduces material for air flow to enter and exit again not needed but nice add on

For your rotating kit check out Molnar technologies

[EarlyWormEatsTheBird]

If you run those heads consider running aftermarket valves as 1 option
Not necessarily needed but will help more flow without touching ports

REV makes nice valve which are back cut and this makes them not only lighter but reduces material for air flow to enter and exit again not needed but nice add on

For your rotating kit check out Molnar technologies

Hey thanks for the input, that would definitely be worth considering. Where could I find these valves?

[Jerry peachuer]

Hey thanks for the input, that would definitely be worth considering. Where could I find these valves?

Any decent cylinder head shop can get these for you and install them because they need to be matched to each valve seat

Springs locks and retainers and clean up will be approx 600-750 price range

To show what's possible check out factory stock racing class rule book requirements. Granted these are very talented drivers but there doing this et with .480 lift cam max with iron heads but all the duration they want

These are no joke engines but alot can be done with a cam and iron heads in the right hands

Don't get me wrong nice set of heads per above and matched cam is prob the best approach

[xctasy]

335 hp net at 5250 rpm and 369 lb-ft at 4000 rpm with iron GT40P heads that were CNC ported to 212 cfm. Roller rockers, Cobra roller cam, and the GT40 Explorer intake wasnt able to take the stock 5.0/GT40P combo past 295 hp net and 321 lb-ft.

The Trickflow EFi or some upgraded Cobra R 4.6 or Australian Boss 260/290/DJR 320 bellmouth and 88 to 90 mm MAF made 349, 389 and 429 hp; The stock Cobra SVT 5.0 and 5.8 GT40 intakes wont make the 425 hp Ford Racing Parts claim without an aggressive loose mid rang torque Andersons N41 or Woody or Buddy Rawls style cam. If the total combination flow is improved youll make 425 hp with a much less aggressive cam while making much better mid range torque.

Its your choice about how you appoint your engine and how and what you spend your money on.

Engine power increase is not proportional to capacity if the port, intake, exhaust and cam dont meet the Pipe Max, Stan Weiss power peaks decreed for your engine size. You always end up with proportionsl torque gain for 29 or 45 extra cubes, 10% or 15%. But unless your cam or intake and head combination isnt restricted, you wont get 10 to 15% extra power unless you do some big geometric changes. If its torque your happy with, then go 347 with 1.169 deck hypereutectic pistons and beg and save up for a great intake as well.

To avoid the minimal bulkhead and cam to crank area cracking, use a neutral balance crank and the Aussie crank girdle. Upper Palmear ties, people say no evidence that they stop block cracking, but unless you add a SMP Dart or FRPP block, you risk scrapping your investment.

The 5.0 is a downgrade of the best 1957 Y block without the fully counterweighted steelcrank the 312 T bird engines had, and the all iron 302 had 130 pounds of iron taken out of it for its first year as a HP 289 in 1963. 250 thou walls went down to 190 thou, and after 1969, cylinder walls were downgraded in Brinell hardnesses below 220 and thickness to 130 thou from the 250 of the Y block and perhaps 180 of some of the best HP 289s. All strokers incur extra risk that you are maybee gonna gamble away that rebuild cost.

Having another 65 pounds of iron in the block is a safegaurd, but it costs a cool 2500 extra.

[EarlyWormEatsTheBird]

Thanks for the information. Not gonna lie, did not really understand all of it. Just for clarity all I'm looking to do is rebuild my engine with a stroker kit and upgrading to a more radical cam in the process until I can buy better cylinder heads. Right now I'm running the carb style performer RPM which is a pretty solid intake manifold as far as I'm tracking. Are you saying I would be able to break 400hp with my GT40P heads I'm currently running though?? If so, what cams and intakes would be a good choice? I'd also be inclined to use that valve replacement that was recommended above. Thanks for your time.

[xctasy]

Thanks for the information. Not gonna lie, did not really understand all of it. Just for clarity all I'm looking to do is rebuild my engine with a stroker kit and upgrading to a more radical cam in the process until I can buy better cylinder heads. Right now I'm running the carb style performer RPM which is a pretty solid intake manifold as far as I'm tracking. Are you saying I would be able to break 400hp with my GT40P heads I'm currently running though?? If so, what cams and intakes would be a good choice? I'd also be inclined to use that valve replacement that was recommended above. Thanks for your time.

No, those heads top out at about 380 hp if everything is gasflowed.

The 2002 5.0 Explorer/Mountaineer based short deck factory 342 cubic inche 5.6liter Ford Falcon T3 250 and 250 Pursuit pickups made from the last US cast OHV 5.0 Windsors. Those engines were was phased out of production from SUV destined units, with the last being sent to Australia. These Windsors were then hand assembled by Tickford Engineering and turned into the most powerful normally aspirated EFI Windsor V8 made in the world. It was stroked to 5.6 liters and boasted to 335 hp at 5250 rpm and 369 lb·ft of torque at 4000 rpm with ACL pistons and a factory long stroke 3.40" crank and 5.35" rods.

It was the old 5.0ltr to start off before Tickford stroked it. No wonder why you see alot of these older fords stroked to 347's.



Problem is the rod ratio for one is 1.5735:1, so it looses 10% of its power with a 21 % l/r ratio loss. A same spec 357 with 30 thou over pistons and the same cam, head and induction would make 385 hp at 5500 rpm, and around 395 lb-ft at 3500 rpm, with just a 75 pound weight pently.

From the often crtical LS1 Aussie forum http://www.ls1.com.au/forum/showthre...ford-T3-250kw&

From just above idle in the Ford there was a strong surge of torque that made the car very quick.
The car could trot around the suburbs using just third and fourth gears most of the time. But stir the engine up and it really started to hammer along, with performance similar to the best a current XR8 can deliver.
It was a good cruiser, too, and would be a welcome companion on any interstate jaunt, were it not for one thing: its incredible thirst.
Even driving sedately on the freeway, don't expect to use any less than about 17 to 18 US miles per gallon. Around town, especially if heavy with the accelerator, you could easily see 11 US mpg as average consumption.

The engine's other big downfall was its vibration. Possibly because they were hand-assembled, some seem smoother than others, but even the best is noisy under load and fairly coarse during hard acceleration. Of course, for many owners of high-performance cars, a bit of noise and harshness only contributes to the involvement.
Transmission choices were a five-speed manual or four-speed automatic, and, given the massive torque available, the automatic is entirely viable.
The 5.6-liter engine was made optional in Tickford's TE50, a more upmarket, Fairmont-based TS50 and in the Fairlane-derived, long-wheelbase TL50.
Unlike the XR6 and XR8 versions of the AU Falcon, you don't get the quad headlight treatment, but you do get a more restrained presentation that is still different enough to separate the cars from their non-Tickford-badged relations.

5.6 liter 342 cubic inch , 335 hp Aussie Import Explorer V8 with stroker crank, rods, pistons, and 80 mm MAF intake, 2002 Falcon Pursuit 250/ T3 Tickford engine

[xctasy]

And the mimimum cam an intake specs...

See http://www.autospeed.com/cms/A_2370/article.html for details in metric. A tall deck, long rod 347W with Aussie ACL pistons should make a very easy 385 hp in EFI form with the right intake and exhaust.



MINIMUM FOR 347w BEST BANG FOR BUCK,

GT40P heads, with 1.9/1.64 valves and port work mainly on the exhaust side.
1.6:1 rockers
The 4% capacity increase should bring the compression up to 10.5:1
At very least, a Crane 2031, which is a 0.513/0.529, 276/282 duration.050 inch Lift: 214 int./220 exh. With 1:7 rockers and AFR 185 or 165 heads work better Piston to valve than the stock gt40's...piston to valve clearance is an issue with 1.7"1 rockers on a stock head.
Explorer manifold with 70mm tb, and a ford lightning 5.0 90mm MAF
balance the bottom end.
msd edis 4 ignition system
4 into 1 headers, twin 2.5" into single 3" exhaust

BEST 400 plus hp BUILD USNG JUNKED T3 ENGINE PARTS

− AFR 185cc Alloy heads- 60cc chambers, modified pedestal mounts
− Comp Cams XFI 5.0 Stroker hydraulic roller camshaft- 236/248 @ .050", 286/300 total, .579"/.579" lift
− Yella Terra 1.6 ratio adjustable Aluminum Roller Rockers
− Full ARP Head, rocker and main studs
− Full Felpro gasket set
− Isky adjustable guideplates
− Trend hardened chrom-moly pushrods
− PAC Beehive springs and Comp lightweight retainers
− Crane hydraulic lifters
− ACL Race series rings and bearings
− Rollmaster double row timing chain with nitrided gears
− Stock 302W roller block- factory bored .020" oversize, torque plate honed
− Stock T3 ACL Hypeurtectic pistons, dished and notched (9.7cc)
− 5.35 rods shotpeened with ARP bolts
− Aftermarket 3.40"nodular iron stroker crankshaft
− Stock T3 Intake manifold
− Stock T3 82mm throttle body
− Stock T3 laser cut main girdle
− Stock T3 oil pump and sump
− Stock T3 fuel pump and fuel lines
− Bosch 43Lb injectors
− 4 into 1 ceramic coated s/steel extractors, twin hi-flow 3" cats, twin 3" stainless steel all the way with X pipe, lukey Race mufflers and twin rear resonators
− AU Edit- extensively tuned by Simon from Xtreme Ford Tuning
− retuned BluePower chip
− MSD DIS-4 ignition system
− Walbro 255lph fuel pump
− MSD Blaster 4 tower coil packs
− MSD 8.5mm Super Conductor leads
− Launch control (2 stage RPM limit)
− Ford Lightning 90mm MAF
− 100mm intake assembly and shielded custom CAI with K&N filte

The Receivers and Managers of Automotive Components Limited (Receivers and Managers Appointed) (In Liquidation) (ACL) announced on Monday, 29 April 2013 that ACL is being offered for sale. The piston are around and going cheap.

site http://catalog.acl.com.au

[erratic50]

What are your goals?

a good set of AFR 165 heads with 1.7:1 rockers and a stock HO cam with a decent intake and exhaust will break 400 at the crank on a 302.

The only real reason to bore an engine is cylinder wall taper causing ring seal issues. You usually can’t find more than 1-2 HP or ft lbs going from 302 to 306.

New rod bolts on the factory stuff and some new rings, balance it and viola

Lots of stuff to build upon but 302 blocks aren’t particularly strong so it’s important to keep goals in mind

Rod ratios are a problem on 3.4 or 3.45” stroke in an 8.2 deck block. It can impact longevity of the shortblock. Longer strokes do increase load on the cylinders at RPM too which can be rewarded with a broken block

I did an AL head 331 for my 85 Saleen clone. Custom cam, etc

I have a 353 for my 86 build. That’s a Dart block 3.25 stroke, 4.155 bore

[Jerry peachuer]

I ran a 331 with 351 worked heads i can share specs and flow numbers later if interested
My cam was ran 4 degrees advanced
My compression was 9-8-1
351 heads were milled and ccd to 59cc
I ran a 351 race port intake gasket to port match intake
Dual valve springs
Rev valves with plus.05 valve keeper location
Ported stealth dual plane intake
1.6 roller rockers
6.200 trend pushrods
Centrrforce clutch
670 street avenger carb 74/74 jets
Distributor from performance distributor curved for my setup (this alone was big improvement)
410 rear gear 5 speed
2960 weight
Shifted at 5600 rpm. For 600 more rpm you spend much more money

This was really a fun setup I raced a 04 lightening on the way to work and he was at my quarter panel and we both spun leaving the light and hit it again
I also pulled in 3rd on a laguna Seca mustang twice on woodward he was passing me as I shifted to 3rd his car sat there for second as I was pulling and he was ripping but if I had 430 gear would of been game changer I believe at least to top of fourth
It broke crankshaft about 1200 miles but other than that it ran hard for light to light fun car
2600-48000 powerband was short but everything worked for it as it spun but hooked quickly and tach'd up quick
Wasn't fast but kept you busy shifting and the extra torque was noticeable from 302 and 306s I had in past

I'm still using same heads on 302 with same intake its fun but doesn't put you in the seat fun

Use those heads as is with maybe valves and the correct springs and you will have nice torque
And short shift it and add some gear

[Jdsgallops]

I would not waste my time with P heads on a 331 or 347. Although they can work well in the right combo last I heard there was still no one that broke 300rwhp with either gt40 or P heads. Some of the factory stock guys may have but that would also be a very tempermental street engine. I totally get the need to budget but there are a million 302 blocks out there. Scoop one up and build it instead of your current one. Someone will give you nearly enough cash for a complete well running engine to pay for a good set of used heads.

My 331 recipie is this.

Scat rotating assembly in a stock block
Afr 165's
Custom spec cam
Stock ported 95 cobra intake

And lots of attention to the little details. This netted me 320 rwhp on a Land and Sea load bearing dyno(roughly 350 dynojet) at only 5300rpm. More impressively though average torque through the rpm range was 333lbft with a peak of 363. Enough area under the curve to get my 3600lb car into the 12's on a true street tire. Trapping at nearly 112mph puts it at 400fwhp and under ideal conditions an 11 sec time slip.

Simple reliable fun.

Before I could afford such luxuries I spent a great deal of time researching cylinder head porting. Thus my opinion of the GT40/P head is this. All SBF heads are created the same. Gt40, DOOE 351, E7's. They all have slight variances but are functionally the same. The stock 302 head generally flows around 150cfm on the intake. The GT40/P/DOOE heads flow about 180, or the same as a stock SBC head. Would you use a stock SBC head on a 350? This number is easily achieved on a stock E7 head with simple bowl work. Therefore even the stock GT40 needs port work to truly make any power. Since all these heads are basically the same all a GT40/P/DOOE head gives you is less work in the porting department as an E7 or a 289 head. Once the port is developed correctly on any of the heads it will virtually look the same. Which begs the question is the premium of the GT40/P/DOOE head worth the money?

Yes I have had a pair of each of these in my hands at some point in time or another. And ironically a properly developed, even by an amateur like myself, ported stock E7, 289, etc.... head will flow almost as much as the early aluminum heads throughout the entire curve. And I have the flow sheet to prove it.

That out of the way a proper cam for a restricted flow head like the P head and even an AFR 165, which could also be considered a restriced flow head by some, will be vastly different.

Do yourself a favor. Do everything at once even if you have to take a little longer to get it done. You will be much happier that you did.

[Jerry peachuer]

Agree ^^

[xctasy]

Ford USA was always avoiding factory merchandising of true 1969 style 351 W or 1967-68 GT40 Le Mans heads. That space was always ocupied by 205 cfm 2V Cleveland or 265 to 275 cfm 4V Cleveland or Boss 302/Boss 351 heads.
Hence the aftermarket Pro 1 AR or TFS or SVO alloy Y and X heads were supposed to fill the 205 to 255 neich.

In Australia, the best factory closed or open chambered 302C or 351C heads from 1970 to 1985 were matched by the GT40P heads, and they are really under-rated factory castings found on Exploders and Mountaineer 5.0s after 1997 or so. Lots around.

See https://fordforums.com.au/showthread.php?t=86696

Despite horrible valve springs and short valves with less size than some of the SVO aluminum aftermarket heads. The GT40Ps were are great small exhaust valve emission head that out flows the 190 cfm C9 351W and the better D0 heads with the Thermactor exhaust bumps. Called GT40P's because they sit above the Le Mans 289 Shelby GT40 castings in intake and exhaust flow, despite a vastly smaller intake and exhaust valve. Don't ever forget, in two versions of the Quad Weber and Hi Riser Twin 585 cfm Holley 4bbl 1967 GT40's made in England, it was a true 165 mph, low 14 second, 380 hp and 326 lb-ft engines in that Ford Advanced Vehicles car.

The GT40P's were CNC machined for a 220 cfm intake port, up from 200 cfm stock in the T1/T2/T3's. This is a GT40x/GT40Y/X303 aluminum type head, but in iron, still with the stock 1.84 intakes and the stock small exhaust valves.

[brian.aughe]

Delete

[xctasy]

See for validation of the much higher GT40P head flow. 200 stock, 220 cfm CNC machined by Yella Terra.

https://www.fordforums.com/threads/w...n-eb-el.60026/

[Jdsgallops]

There is 0 difference between a GT40 intake port and a P intake port. The only difference is the exhaust port. For a junk alphabet cam that might be needed, but try to find a P specific header nowadays. Any decent aftermarket cam will have split duration intake/exhaust lobes thus any gain by the P exhaust port is negated, IMO. The Y and X heads are also largely a waste of money. I recently sold some parts to a local guy here that had them on his car. Back from a dyno tune and it made 268rwhp. To say the least he was disappointed. The GT40 line of heads never lived up to the hype in anything but a race application.

The thing to remember here is that no professional head porter looks at peak flow numbers. They look at actually flow versus theoretical maximum for the valve opening size. This is where port development comes in. When you start looking at heads from this point of view things look very differently. And the AFR165 becomes king daddy.

Cnc ported P.heads that flow 220 are not impressive at all. My flow sheet is higher than that, though not much and is all hand work.

[xctasy]

Well said. I think when you go back and re-look, I am in agreement, only point I'd make is Ford Austrialia ended the reign of the 5.7 liter alloy LS-1 Gen III-engined Holden Commodore SS as the king of affordable Australian V8- performance cars. And it did it with 29 year older tech and before the 5.0 got another 40 cubes, 40 hp and 48 lb-fts.

In the USA at the same time, Ford were worried about how everything would fit in with the Mod 4 cammer. Ford USA were Luffing....means changing the elevation angle of the crane boom/jib. That old iron 5.0 and the 5.6 stroker is very much a Boss 302 or Boss 351 with cheaper parts and less focus on peak air flow.

And the engine! What about the engine? Love it. This has got to be the dear old Windsor V8's finest hour....The new XR8, then, is the winner. It's a much more rewardingly responsive drive than the SS, and now deliviers simarly thrilling performance.

We just found 232 cfm@500 with a modded set of T3 GT40P heads, and they were stronger everywhere in the lower ranges.

More important here is the average port cross section, and u will find that with increasing the cross sectional area too much, you can saturate the cylinder. This will cause the engine to require extra timing, etc when being mapped, causing inefficiency and bad fuel consumption. sure it will make the power up high, but for a daily driver, the cast iron heads are enough.

Dont get me wrong, im the first person to want more power, however you need to remember the application and budget. $2400 for heads, then manifold, then you need to up the RPM limit, then you need to re-do the short, whilst its apart u might want to stroke it, etc etc.

Next thing you know, your in the bin for over 10 large, and for what result?

Ive tried talking customers out of this gear with XR8's, but they cant help themselves. Next thing you know they are making 335 flywheel rwhp, but the cars aren't as fast as a 295 flywheel hp cast headed deal on the road because of wheelspin and acceleration.

Check the qtr times on the alloy headed T series, and the AU220 with the cast heads. Also check the fuel economy and driveability.

The gentleman who started this thread requested tech info in cast heads. So, if you are technically minded give him the advice he has asked for. If you are just a magazine reader, dont comment. If you want to recommend alloy heads, give him the full story, not an opinion. The correct questions would have been "what's your budget" or "how often does the car get driven".

The things worked out in port profiles were done on a dyno, not a flow bench.

[Jerry peachuer]

My opinion is buy vic jrs but buy them (bare) and have head shop assemble with your springs when you purchase your cam

My heads and intake were worked pretty far and my flow number at 500lift is 214.6/183.5 w/pipe on exhaust.. still running them today buy i kinda kick myself because my buddy runs 10.60 with his box stock vic jrs and vic jr intake on his 331 but has 13 5 1 compression and very large roller cam and 5500 stall
Non pump gas motor so I think same power and outcome can be had with a pump gas 408 and vic jrs and large roller cam with 430gear and 5 speed street car we will see

Vic jrs bare are 600.00 each
I paid $1302.00 for my heads with port and bowl work with studs springs guide plates aftermarket valves and seals locks and retainers and roller rockers with intake porting as well back in 2009

Wished I didn't they will forever hold back hp possibilities

[Jerry peachuer]

However- i hope you do put non alum heads on the shortblock because you will get to experience the iron vs the alum and you will firsthand feel and see what your money purchased you. Its ok to proceed as you stated the world will still turn and tomorrow will still be there it will just cost you a new set of intake and head gaskets and some fluids and a solid day to swap it all over when you purchase Alum heads or any other type of head

I was in the same boat when I built mine just be very careful not to buy things (twice) this sucks
Hard to spend 2500.00 for a gain of 60 ish rwhp ... I get it but that 60 is very noticeable also

If you do build your shortblock first and heads later just try to dial in what heads you want and stick to that recipe because you have to consider what pistons work with valve design as far as sizing and valve reliefs and inline valves Vs canted or non-inline valves
This is why I stated valve upgrade only on the stock castings per my original post reply
And comment above about headers for the p heads are unique so good comment on that as welle

Edit: valve upgrade only on stock heads meaning don't spend money on port work spend it on better heads and the unique header will set you back a couple of hundred as well so caution on that also

[Jdsgallops]

Just putting bigger valves in with no port work is a huge waste of time and money. The whole bowl needs to be worked to take advantage of the bigger valve. Just putting valves in will cost at least $350 between cost of valves and machine work. That is a good chunk of change to put towards a good aftermarket head.

[Jerry peachuer]

Push rods or polish rods

typo lol

[Jerry peachuer]

Depends on budget and how long it takes to save for heads
You will need valve seat lapping work regardless I would not just bolt them on and you could sell them for at least some of your money back if done correctly
350 vs 1800 is a savings but I do caution about the twice comment above
Shortblock is 2400-2800 balanced less cam and pan and clutch and p rods and dizzy and waterpump
Save for another 1800 plus intake and roller rockers and polish rods


I get it

[Jdsgallops]

Lapping valves doesn't do anything for the big lip that will impede airflow from a proper 3 or 5 angle valve job. There are hard numbers on how far that valve job needs to go into the bowl. If you look at all of my above comments you will see I have talked about developing the port. Throwing bigger valves in without the foundation to support them doesn't gaurentee any benefit. You also haven't taken into account that his current heads may need guides and resurfacing. And then you have that whole pedestal mount rocker thing to deal with. Which is why when on a budget you don't buy new you find good used products. I bought my 165's from a buddy bare with valves and built them myself. Always ways to get them cheaper than $1800.

[Jerry peachuer]

I agree
I never suggested porting and I have real experience with porting something you shouldn't

However those valves are ground to fit stock valve size no bowl work required (1 option)
Same head he currently has with rockers already and he already has the headers
He is asking only if anyone has ran gt40Ps
Not anything related to porting
However if he builds a new engine you will want to seal the combustion chamber and you know this
Being a head porter and being these valves fit stock size oem holes and you need valve work anyhow and requesting a better cam you need new springs so this is all being removed for resealing the chamber either lapping or cutting valve seats its all apart and adding 125.00 stainless steel back cut valves will help him get by for now with strong torque than stock
Not ideal but he already owns everything and he's saving for AFRs

If he chooses a non in line head then he may have piston to valve relief material issues to consider
Afr 165 are nice and used is the best price

You have received a deal on used heads that not everyone will find and being a head porter you know what alot others don't
Your comparing real data Vs. word of mouth or magazine land articles (which is great)

I agree with not touching ports on iron heads however if I was to build a stock motor I would definetley get the valves to seat whether they are lapping or ANY angle valve seat cutting period
Being he is upgrading cam ge needs new springs possibly and how many of us has the equipment to set spring heights and check pressures ? Can you bypass this absolutely until you hit your new piston on your new stroker during valve float

My valves costed 125.00 and 120 to cut the seats for them and all of the exhaust seats were removed and new ones installed for longevity

He also has intake and he can add AFRs weeks or months later without any wasted money except gaskets and possibly valves that you can resell these heads with a receipt to a non stroker build person

I don't know anyone trying to increase stroke with higher lift cam using stock heads that are excited with the results

The dyno will disappoint and make you humble

[xctasy]

The deal is you make your own luck.

GT40P's take the Aussie headers.




Ford Performance Parts M-9430-P50 headers from Summit require some pipe work and some o2 bungs, but they have the 7 th pipe shifted.




The parts for iron head updates exist everywhere if you do the research. And those Iron GT40P's are the unmatchable economy proposition, and Ford Australia proved it.

The early cast iron reproduction iron headers for 289 HiPo's allow the 90 degree Chevy boot equipped GT40P's to match up.

GT40P's are the sh!+, because stock K code iron cast headers fit.

This is why the GT40P heads are so inexpensive.

Even Scott Drake K code C5ZZ94301DE re-hashes of the old C40E 9430-A / C40E 9431-A downstream Air 289 K code code iron headers work on GT40P's and you can use a split duration cam to suit backpressure. We know so much more about exhaust flow motion now.






My best response on all of this is :-In late 1969, ex USA Ford Drag engine guru Big Al Turner, newly at Ford Special Vehicles in Australia grabbed

1. bare USA Cleveland plant 4V M code Canted valve castings

2. from source Ex Canada, and

3. instead of using Cleveland Boss 302 castings,

4. did all the solid lifter conversion and valve supply and machining himself.

End result? QC Phase II Slapped on a 750 cfm 4-BBL Equipped 16 thou de-decked 351C 4V M-code block , in a 3550 pound weight car (without rider and gas). With two people and 50 pounds of gas, it Did 14.1 second quarters, 145 mph, and made 340 hp net at 6500 rpm with a custom Windsor 289 K code style 310 degree at lash solid lifter cam with 228 degrees duration and nearly 0.519 " lift.

In 1971, QC Phase III 350 hp net at 6500 rpm with a downgraded duration 300 duration, 243 degrees at 50 thou cam with 0.505 lift. 141-144 mph on the 6150 rpm rev limiter, 13.9 to 14.7 second quarter mile times.

In 1972, QC Phase IV 380- 390 hp at 6500 rpm, and with a 300 duration, 243 degrees at 50 thou cam with 0.505 lift. 153 mph on the 6150 rpm rev limiter, but 170 mph with it removed.

Ford Australia's Al Tuner got the ex Repco engineer to re dyno engine combinations to get an extra 50 hp without


1. any short or long radius port blending from stock M code heads.

2. No forged pistons,
3. no 4 bolt blocks from the factory,
4. no thing but chamber work.
5. The off the seat cam duration was reduced over the 2 years it was developed. None of it was Boss 351 except the balancer and the head gasket. It was just long, lonely nights spent over the engine dyno, with late night durability trials at 170 mph. That's how to develop a cylinder head. Ford USA did all the flow bench stuff. The Aussies used lower tier parts, and then developed them without port area or intake port volume changes.

6. Compression ratio was dropped from 11:1 to just on 10:1 by removing metal from the 75 cc closed chamber heads.

7. The Exhaust was Tri Y tubing headers, so no Super Cobra Jet style split duration cam. The whole cam shaft timing got scaled back, with increased 50 thou lift intensity, and peak lift stayed the same.

In essence, an earlier day David Vizard/Stan Weiss Cylinder head Optimization Program. With a die grinder and linishing on the iron chambers


Firewood sometime burns hotter, it seams. When you fetch it yourself. You add the Quality Control. Be a GC..



A nice Ford approved aluminum casting is my first choice, but the risks for other castings from all over the world are easy to mitigate if you can do the quality work yourself. Or , at least, command that some one else does it.



Showin' ma age, but, ahem, back in the day, we had the first aluminum heads for small block non 335's in 1989. Way later than the 1983 alloy 335 SVO's. Windsor guys have had it good ever since Alan Root and Ken Duttweiler did the early inception of the J302's.





Its 31 years on, and thank G""d, its a buyers paradise now . Head temper, casting porosity, and the risk of hitting a void or a water galley still exist, but people have been putting years and multiple rebuilds on early aluminums.



Pictures of the excitement in Australia in 1989. I was there. Great time to have America casting alloy heads, but we were casting Alloy head Fords way before then, and its sad the big old Giant didn't just make A3, B3, D3 335 canted valve headed cars in 1983 from Jack Roush's empire. Never mind. So by 1989, Alan Root AR-1/ Pro-1/J302's were the bomb....