Exploring Options For A Budget Engine Build on 84 GT 5.0

[84StangSVT]

Hey guys, been thinking about this lately and it is something that I would like to shoot for this winter.

That being said, let me throw a couple things out there so maybe we can try and keep this from being so head turning for me.

1) It has been forever since I have even been in a motor, it will basically be learning from scratch again. The last time I have done this has been 21 years ago and most of the main work was done by my uncle, who was an ASE Certified Tech and did it for a living. I promise you, I have forgotten most of what he taught me about the inner workings and what to do.

2) We can debate roller vs flat tappet all day long but I would assume avoid it at this time. I would like to retain the #'s matching block and what not as it runs strong and I have no real desire to wind the RPM's into the stratosphere. I know decent, fun, streetable power can be made from a flat tappet motor on a budget and that's where I'm at right now.

3) Would like to keep the budget around $1000-$1500. Obviously this will be hard to predict until the motor comes apart and I can see what all is still usable.

I don't have a definite HP # I want to achieve, I just want to find the most bang for the buck. I know I can buy the Edelbrock 2027 top end kit for about $1700 and probably be happy with it, but I think with some of the expert knowledge on this forum I can get a little more out of the motor for the same or less money. Plus I get to learn more about this subject again.

Here's some info:
Stock Motor
Holley 4180c or Edelbrock 1406 carb
BBK Shorty Headers 1 5/8"
BBK Off-road X pipe 2 1/2"
Dynomax Super Turbos - Currently 2 1/4" and dumped - Will be upgraded to 2 1/2" with 2 1/2" tailpipes.

Let me know what you all think. Thanks!

[FoxOnABudget]

Do you have any specific power goals that you want to reach? With $1500 you can build a reliable, decently powerful 302

[84StangSVT]

Do you have any specific power goals that you want to reach? With $1500 you can build a reliable, decently powerful 302

I really don't have a specific goal honestly. Obviously I would like as much power as possible in the price range, but I want it to be streetable with good low to mid range power. I don't race so I don't need power that comes on only above 5000. I figure where the car left the factory with 175 hp, anything is bound to be better.

[FoxOnABudget]

I really don't have a specific goal honestly. Obviously I would like as much power as possible in the price range, but I want it to be streetable with good low to mid range power. I don't race so I don't need power that comes on only above 5000. I figure where the car left the factory with 175 hp, anything is bound to be better.

Since it is a street car then I would suggest doing a dual plane intake, mild cam, and a set of aluminum cylinder heads. You could probably go to a swap meet like Carlisle and find all that stuff and be under that budget.

[84StangSVT]

Since it is a street car then I would suggest doing a dual plane intake, mild cam, and a set of aluminum cylinder heads. You could probably go to a swap meet like Carlisle and find all that stuff and be under that budget.

That's pretty much what I'm looking for, just have no idea what parts/brands/specs to start matching together. I hope for the money that will be spent, it will be an optimized package not a hodgepodge of parts that may not play well together.

[FoxOnABudget]

That's pretty much what I'm looking for, just have no idea what parts/brands/specs to start matching together. I hope for the money that will be spent, it will be an optimized package not a hodgepodge of parts that may not play well together.

For the intake I would go for an edelbrock performer 289 and the heads Edelbrock E street heads. I couldn't tell ya what cam to do as I have never done a build on a flat tappet 302, I have only done roller cam engines

[bwguardian]

How many miles on the clock? I understand wanting to keep the numbers matching block as that was my goal several years back...along with also keeping it looking stock under the hood. Fire it up and one can tell right away it ain't.

The '84 power plant came with cast pistons and will be okay for a mild engine like what you are talking about. If it all looks good you could do a light hone on the cylinder walls and install fresh piston rings. From there, things you will want to do is install a new oil pump, timing chain/gear set, etc.

For the cam, look at Lunati as they used to have a really nice Street Master cam I utilized back in the day. It was a flat tappet unit that had somewhere just north of .500" of lift and can't remember the LSA, but probably around 110*. I would stay in that LSA area with a carburetor motor...108*-112*.

That motor was 8.4 to 1 on the compression...as was the '85 like mine. The easiest way to raise that and is with the heads. The factory heads had huge combustion chambers...like 68cc-70cc. Really not going to make alot of difference on this motor with aluminum versus iron so see what you can find. I put the GT40p heads on mine and they cc'd to around 59cc which put my motor around 9.5 to 1. When you start getting larger on the valve size you might run into having to fly cut the pistons. Back in the day when I did my '82 I installed 1.94 intake and 1.6 exhaust valves and had to fly cut the pistons. The valve reliefs were deep enough but the diameter was not large enough.

Match the intake to the rest of the motor and what you plan on doing with the EGR and/or thermactor system. I went with the Ford Racing unit which does not accommodate for the EGR system. You will definitely want to stay with a dual plane unit but might look at the Performer RPM depending on the cam and heads.

Lastly, take the original 4180c and rebuild it with a few tweaks you can search and find here. This is what I did and have been really happy with it as it is a really good carburetor.

The only other thing you might look into is a gear set change. If you have the factory 3.08 you might look at a 3.55...or better yet, look at upgrading that stock 7.5" unit to the much stronger 8.8" unit. This was also done on mine and it has a 3.27 gear for an auto car and it is just enough for me.

[84StangSVT]

How many miles on the clock? I understand wanting to keep the numbers matching block as that was my goal several years back...along with also keeping it looking stock under the hood. Fire it up and one can tell right away it ain't.

The '84 power plant came with cast pistons and will be okay for a mild engine like what you are talking about. If it all looks good you could do a light hone on the cylinder walls and install fresh piston rings. From there, things you will want to do is install a new oil pump, timing chain/gear set, etc.

For the cam, look at Lunati as they used to have a really nice Street Master cam I utilized back in the day. It was a flat tappet unit that had somewhere just north of .500" of lift and can't remember the LSA, but probably around 110*. I would stay in that LSA area with a carburetor motor...108*-112*.

That motor was 8.4 to 1 on the compression...as was the '85 like mine. The easiest way to raise that and is with the heads. The factory heads had huge combustion chambers...like 68cc-70cc. Really not going to make alot of difference on this motor with aluminum versus iron so see what you can find. I put the GT40p heads on mine and they cc'd to around 59cc which put my motor around 9.5 to 1. When you start getting larger on the valve size you might run into having to fly cut the pistons. Back in the day when I did my '82 I installed 1.94 intake and 1.6 exhaust valves and had to fly cut the pistons. The valve reliefs were deep enough but the diameter was not large enough.

Match the intake to the rest of the motor and what you plan on doing with the EGR and/or thermactor system. I went with the Ford Racing unit which does not accommodate for the EGR system. You will definitely want to stay with a dual plane unit but might look at the Performer RPM depending on the cam and heads.

Lastly, take the original 4180c and rebuild it with a few tweaks you can search and find here. This is what I did and have been really happy with it as it is a really good carburetor.

The only other thing you might look into is a gear set change. If you have the factory 3.08 you might look at a 3.55...or better yet, look at upgrading that stock 7.5" unit to the much stronger 8.8" unit. This was also done on mine and it has a 3.27 gear for an auto car and it is just enough for me.

I honestly do not know the true mileage on it as the odometer didn't work when I got it. It showed 46733 when I got it, but judging on the condition of the car I would think it is safe to say that it is was 146733 easily. Without tearing it open and seeing what is up inside, it will be hard to say what the internal condition looks like. I know for a fact that this motor has been apart at some point in time as there is the tell tale RTV signs on the front cover, oil pan and heads. How far it was down and what was done to it is unknown to me. I know it runs fairly strong now with no odd noises coming from the valvetrain and the car uses absolutely no oil. That gives me hope that she is still fairly healthy.

I figured I would give it a new oil pump, timing set and re-ring the pistons while I was in there. I suppose new rod bearings might be a good thing to do also?

Cam selection is something that I really don't know a thing about, as well as installing a new one and making sure it is installed correctly. I want to learn and I'm sure with the proper instructions, it can't be that bad to get it right. As for heads, again I don't know much about them. If I get a set of GT-40's, what needs to be done to them to make them work with a flat tappet setup?

As for an intake, my car has had a smog delete done on it. All emission equipment is gone.

I figured the 4180 would be a better choice than the Edelbrock 1406 that came with the car, that's why I bought one some time ago. I need to rebuild it and get that good to go.

Luckily someone in the past has done the 8.8 conversion on my car and it does have a 3.27 gear in it which has suited me fine so far. I don't know if I will change to a steeper gear since I'm not out to pull the front tires off the ground.

[bwguardian]

I honestly do not know the true mileage on it as the odometer didn't work when I got it. It showed 46733 when I got it, but judging on the condition of the car I would think it is safe to say that it is was 146733 easily. Without tearing it open and seeing what is up inside, it will be hard to say what the internal condition looks like. I know for a fact that this motor has been apart at some point in time as there is the tell tale RTV signs on the front cover, oil pan and heads. How far it was down and what was done to it is unknown to me. I know it runs fairly strong now with no odd noises coming from the valvetrain and the car uses absolutely no oil. That gives me hope that she is still fairly healthy.

I figured I would give it a new oil pump, timing set and re-ring the pistons while I was in there. I suppose new rod bearings might be a good thing to do also?

Cam selection is something that I really don't know a thing about, as well as installing a new one and making sure it is installed correctly. I want to learn and I'm sure with the proper instructions, it can't be that bad to get it right. As for heads, again I don't know much about them. If I get a set of GT-40's, what needs to be done to them to make them work with a flat tappet setup?

As for an intake, my car has had a smog delete done on it. All emission equipment is gone.

I figured the 4180 would be a better choice than the Edelbrock 1406 that came with the car, that's why I bought one some time ago. I need to rebuild it and get that good to go.

Luckily someone in the past has done the 8.8 conversion on my car and it does have a 3.27 gear in it which has suited me fine so far. I don't know if I will change to a steeper gear since I'm not out to pull the front tires off the ground.

It would probably be a good idea to run a compression test and see how healthy the engine is. One seal you will also want to replace is the rear main. I cannot remember if yours will have the 1 piece or 2 piece, but pull the rear main cap and have a look at the bearing. Heads are not specific to cam/lifter style.

[grabbergreen84]

Pretty sure '84 was the first one-piece rear seal.

[82gt50]

Seems like this kind of power and RPM range is what you are looking for and the engineering has been done by Edelbrock. The heads, intake and flat tappet cam will work together guaranteed.

[droopie85gt]

Just remember if you build a flat tappet engine, you've got to break it in properly and run the right oil. Today's oils have most of the zinc removed and are very hard on flat tappets. If you don't break it in properly and use good quality oil, you'll end up with lobes wiped off the cam.

[84StangSVT]

Seems like this kind of power and RPM range is what you are looking for and the engineering has been done by Edelbrock. The heads, intake and flat tappet cam will work together guaranteed.

You are most definitely correct and most likely will be the way I end up going. I would still like to explore other options and see if I can't get a little more out of it for the same or less cost.

[84StangSVT]

Just remember if you build a flat tappet engine, you've got to break it in properly and run the right oil. Today's oils have most of the zinc removed and are very hard on flat tappets. If you don't break it in properly and use good quality oil, you'll end up with lobes wiped off the cam.

I understand that and am aware of the consequences of not following the break in and using inadequate oil. I like to be different......I ain't skeered!

[E2ZZGLX]

More for less...this is what I like to here! Keeping it basic and simple 300-350hp is no problem...I would start with a roller block, go .030 over with flat tops...this should keep compression around 10.5, recon rods with aftermarket bolts,etc balance the rotating assy. Tried and true B303, with some GT40's, port matched with minor clean up, maybe a set of roller rockers, nice duel plane intake and a 600 Holley. Everything easy to locate and $$$ friendly.

[gt4494]

I run the 1.6 roller rockers on the stock cam and E7 heads. inexpensive and the rest of the setup like you said in the first post. it dyno's at 210hp to the rear wheels. A matched setup that is tuned right is what you need for the street.

[Teal9550]

my first mustang was an 82 GL 302, 2bbl,srod, trx no option car. I decided it was a great idea to change the manifold to put a 4bbl carb on it. When I pulled the manifold there was a ton of sludge in it so I yanked it and did a rebuild. My combo was .30 forged piston .10 .10 crank and rods, comp cams 268 flat tappet cam, gt40 heads, performer rpm intake, 1 5/8 full length headers, this was backed by a tremec 5speed & an 8.8 with 3.73. I never had the car dynoed but with a 100 hp wet shot the car ran 12.70s with a 26x8.50x15 et street. It was very reliable, wasn't obnoxious at idle , got decent mileage and wasn't to expensive. All that being said you could probably put an explorer motor with a rpm manifold, tfs1 cam and be about the same

[84StangSVT]

A year later, it's time to refresh this thread for some on going conversation.

I'm still looking at this possibly as an option as I think it could be fun. Now with the caveat.....with the addition of the FAST EFI system, they recommend running a single plane manifold as they have been known to not run worth a crap on a dual plane. How does that change the build planning?

[droopie85gt]

I don't know why they say that. Fuel is fuel. The cam plays the biggest factor in whether a single plane or dual plane work well. The TBI setup actually should be easier to tune even on a radical cam than a carb because the carb isn't relying on a vacuum signal to draw fuel out. If you check out the Holley EFI tech forums, there is a guy named Danny Cabral on there who has a 460 Bronco. He converted an RPM Air Gap to port injection. Took some work to get the injectors the same height, but even on a big block he wanted to down low torque you only get with a dual plane.

I have the Holley TBI commander system on my 302 with a Wiend Stealth dual plane and a TFS Stage 2 cam and it runs better than it ever did with a carb.

You will give up a ton of torque down low with a single plane. I'm going to go with an RPM Air Gap on my 351W swap. There's plenty of dyno comparisons on Air Gaps versus other manifolds on every type of engine out there and it kills single planes down low and fights them up to 5500 or so depending on the combo. If you've got a street mainly car, how much above 5000 are you going to need? Torque is what makes a street car fun to drive stoplight to stoplight.

[84StangSVT]

I don't know why they say that. Fuel is fuel. The cam plays the biggest factor in whether a single plane or dual plane work well. The TBI setup actually should be easier to tune even on a radical cam than a carb because the carb isn't relying on a vacuum signal to draw fuel out. If you check out the Holley EFI tech forums, there is a guy named Danny Cabral on there who has a 460 Bronco. He converted an RPM Air Gap to port injection. Took some work to get the injectors the same height, but even on a big block he wanted to down low torque you only get with a dual plane.

I have the Holley TBI commander system on my 302 with a Wiend Stealth dual plane and a TFS Stage 2 cam and it runs better than it ever did with a carb.

You will give up a ton of torque down low with a single plane. I'm going to go with an RPM Air Gap on my 351W swap. There's plenty of dyno comparisons on Air Gaps versus other manifolds on every type of engine out there and it kills single planes down low and fights them up to 5500 or so depending on the combo. If you've got a street mainly car, how much above 5000 are you going to need? Torque is what makes a street car fun to drive stoplight to stoplight.

I wondered the same thing honestly but all I can do is go by what I read on most of their site. For some reason they suggest that the mixture to all cylinders will not be equal due to the design of TBI vs Carb and some cylinders may run lean. The state that testing on single vs dual with this system pretty much negates any advantage of a dual plane as the operation is different between TBI and carb.

Again it is way over my head, I can just only make an formed decision on what others have found with this system.

[droopie85gt]

That's crazy talk. TBI follows the same rules as a carb. About the only difference is fuel is sprayed down the barrels in tbi and is pulled out by vacuum on a carb. Other than that you have a fuel vaporized into the air stream. I actually think you can tune TBI to idle well with wild cams that you probably would have a hard time getting a carb to idle.

Any wet flow manifold will have uneven flow. It's a matter of physics, especially on a 302 where the center 2 cylinders on each bank have very short runners and the end 2 on each bank have longer runners. The solution to that has been port injection. Granted with a dual plane and long runners if you have a ton of duration on the cam and overlap you can have fuel puddling at low speeds, but I'd say a TFS Stage 2 is a damn big cam for a 302 and I can get mine to idle pretty solidly as low as 750 rpm and it pulls hard to 6000.

The intake and cam don't care how the fuel gets into the air stream. I'd suggest doing some search for cam and intake dyno comparisons. Find one that fits the rpm range you'll be using and go from there. I'll think for mainly street driving you are going to be MUCH happier with a dual plane and mild cam.

For what it's worth, the Holley C950 TBI on mine isn't even self learning. I had to hand tune it and it runs great with a big roller cam and dual plane. I haven't had it dyno'd but compared to the old combo that put out 275/277 to the wheels, I'd say this puts out 320/320 at least. I'm pretty happy with it...just going to swap to Holley HP self tuning ECU and a 351. With a BIGGER cam.

And I don't remotely claim to know it all. Do lots of research and ask lots of questions.

[wraithracing]

I wondered the same thing honestly but all I can do is go by what I read on most of their site. For some reason they suggest that the mixture to all cylinders will not be equal due to the design of TBI vs Carb and some cylinders may run lean. The state that testing on single vs dual with this system pretty much negates any advantage of a dual plane as the operation is different between TBI and carb.

Again it is way over my head, I can just only make an formed decision on what others have found with this system.

I can understand that the actual delivery of the fuel into the intake may be different between a TBI and a carburetor, but I don't see how that adversely affects the advantages of a dual plane intake at lower RPMs. The TBI inject, I would assume does a better job of atomizing the fuel due to the higher operating pressure over a carburetor. IMHO that should improve the fuel distribution throughout the intake and each runner rather than cause some cylinders to run lean. I would think the carburetor would be more prone to fuel dropping out of suspension in the air more than a TBI and cause fuel puddling or other issues that could cause a lean issue.

I am not carburetor nor EFI expert, but it just doesn't make logical sense to me. At least not the way I understand how TBI/Carbs and wet fuel charges flow in a normal internal combustion engine. FiTech EFI states that their systems do not care what type of intake they are mounted on and will work with either. I think either FAST is visiting Colorado too often and needs to quit smoking the state plant IMHO. or they have stock in single plane intakes!

[84StangSVT]

I think either FAST is visiting Colorado too often and needs to quit smoking the state plant IMHO. or they have stock in single plane intakes!

They are owned by Comp Cams so maybe that's part of the issue.

[droopie85gt]

Comp's here in Memphis....in the hood. So MAYBE they are smoking it up in honor of Colorado!

[BTD]

So everyone clearly missed your budget, which was 1500. You don't need new heads, you don't need a new cam or new timing components. You are a new guy with 302's , just like I was when I started so I will give you all the advice I wish I had, and please just ignore all the expensive stuff they are talking about.

Get the following
A full gasket set from whoever you want - I got mine from Fel Pro but it doesn't matter
A new high volumne oil pump - again who makes it doesn't matter, that's just marketing and personal preference. Graphs and the like don't mean ****
A new oil filter
A new intake of your choice - Doesn't need to be fancy, just that the 83-84 sucked ass for flow, so you need more breathing.
If you carb is okay , just rebuild it - You can totally do that with youtube videos, I did 3 test ones that were 2v, and they came out great
If you want a new carb, get one, but do the research on how to jet it/set it up before hand, as its not just common knowledge, and is not easy. It takes a lot of work and patience

All that you should just need a good socket set and some wrenches to accomplish. It will give you a fresh boost of power, and your car will feel brand new (to you, which is kinda the point)

You can do all that for less than 1500.