C6 and roller 351w questions

[Drake bartel]

To start I'll say that the car is a 80' fairmont that I picked up a while back to use some of my leftover mustang parts on. It has a 3.3 inline in it that burns a ton of oil, but otherwise it's a clean car. The key parts that are going to be going in this car are an e4te roller 351w, gt40 cylinder heads drilled out to fit the 351w, fox length 31 spline 5 lug 8.8 among other things of course. I still have some parts shopping to do and since I'm on a budget im considering a c6 for the strength and durability. I already have an aluminum crown victoria drive shaft that I'll have made to what i need and the proper oil pan so that shouldn't be an issue. As of now my main concern is fitment. First off will the v8 even fit inside the inline 6 k member? I did keep the k member from the parts car that i harvested a t5 from for a different project but either way I'd like to know for certin. Between convertible engine monts, adjustable double Hump cross member, and the k member spaced down will a c6 even be close to fitting? As far as headers are concerned what have some of you done for This? Finally my biggest question, are any c6s more desirable than others? I'm looking at getting one out of an older 80's econoline van but am not sure if it's a good candidate on not. I know the c6 wouldn't be the first choice for many, but everything considered I think it would be my best choice.

[wraithracing]

I am not a Fairmont guy and have never owned one, so I can't 100% confirm fitment etc as I understand there are some differences between the Mustang/Capri and the Fairmont. With that said, I will help with as much as I know in regards to a 351W in a Mustang/Capri.

The inline 6 K member has the motor mounts too far forward for the V8 swap. Yes, you can modify, but the easier choice is a 4cyl/V6/V8 K member.

The C6 should fit the Fairmont, but you may have to massage the transmission tunnel a bit for clearance in some areas, hopefully others can give better details, but I can fit.

Most likely a set of shorty 351W swap headers will be your best option. There are long tube headers for the 351W swap, but many don't fit with the automatics, so make sure to verify that before purchase.

The C6 is an excellent transmission and if built properly should handle any power level you might have with the 351W. The down side is that it only has 3 forward gears and no overdrive. If its an in town cruiser with little to no highway mileage, no big deal. If you need/want to take it on long trips at highway speeds, I would recommend a well built AOD if you want an automatic, otherwise a really well built T5 or an aftermarket Tremec 5/6 speed. Hope that helps and good luck!

[Drake bartel]

Well that cleared up a lot. Now I know ford didn't put the c6 behind many sbf's, so it seems to be a tad bit harder to find one with the right bell housing. With that said would an econoline van be a good donor? They have a row of older ones at my local junkyard, but I'm not sure if there were any variances between the c6's depending on what vehicle they were in. They do also have a few 4 wheel drive trucks that have them, but I'd imagine that's no good for me so the econoline is really my only good option.

[droopie85gt]

It seems with your power level, a C-4 might be a better option. They are much easier to find, will fit better, and today there are companies that can rebuilt them from stock to 1000 hp levels. You probably can find a good core for less than $100.

[Zap's 85 GT]

Yes, you will need a different K-member.

The C6 (if you can find one that fits a small block bolt pattern) is going to sap a lot of power. I had a nice Art Carr C6 with a 2400 stall in my Mach 1 back in the day. I converted the car to a Toploader 4-speed and it felt like the car gained 40hp. Unless you have a super healthy 351, running a C6 behind it is going to net near the same rear wheel power and torque as a 302 with a T5.

[wraithracing]

The other issue with using a C6 from a truck or van will most likely be the position of the shifter linkage. In most case the linkage points up because most trucks and fans are column shifted, but the cars are often floor shifters. I ran into the same issue using a Mustang AOD in a F150, but in reverse.

If you have your heart set on the C6, then the mid 80's to late 80's F and E series vehicles are great options for finding the C6 behind the 351W. You can also probably find an AOD behind a 302 also. As stated you will have to flip the shifter linkage on the transmission to use a normal Mustang shifter, or come up with some other solution. The AOD would be a better option IMHO as it gives you the Overdrive 4th gear. Just make sure you get the correct TV cable for the AOD and you adjust it properly when installing, otherwise you can damage the transmission in short order. Good Luck!

[82MoreDoorFox]

Not sure how far along you are but you can make the C-6 fit. I have that setup(302 w/ C-6) in my 82 motor door. You will have to mod and cut the 6cyl but it’s not that bad.


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[erratic50]

Honestly I’d go C4 or AOD. Cheaper in the end even if you have to build it to hold the power by the time you factor in the “make it fit” parts

There are guys that swear by 4 speed automatic transmission (name escapes me) found behind the 2008 5.4 triton. Only thing is you need an adapter plate and a control box.

[82MoreDoorFox]

Honestly I’d go C4 or AOD. Cheaper in the end even if you have to build it to hold the power by the time you factor in the “make it fit” parts

There are guys that swear by 4 speed automatic transmission (name escapes me) found behind the 2008 5.4 triton. Only thing is you need an adapter plate and a control box.

I fit my C-6 with only mods being the linkage, AOD flexplate , a light massage, and 1 day labor I’m total $150

Stock C3 trans cross member and stock driveshaft. Doesn’t get much cheaper. My engine is sitting 1.5” forward but still fits good



I might have gone c-4 but a c6 was donated. So can’t go wrong.


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[erratic50]

Ouch- 1.5” is an eternity in terms of weight distribution! Think about the axles as pivot points and where that mount is in relationship.

When I moved my boat forward 2” on the trailer the tongue weight increased from zero to around 300 lbs. Basically all I can dead lift with one hand and arm

[82MoreDoorFox]

Ouch- 1.5” is an eternity in terms of weight distribution! Think about the axles as pivot points and where that mount is in relationship.

When I moved my boat forward 2” on the trailer the tongue weight increased from zero to around 300 lbs. Basically all I can dead lift with one hand and arm

The 330ci motor mounts where another 1.”5 forward. I’m using my stock K-member front the 6cyl. My mounts are a little further back. That with some extra 40lbs thanks to the C-6 tranny behind it, I think I’m good. Running as a daily and have no issues.


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[xctasy]

FE 332 and six cylinder engine mounts were made to reposition the small block in the F truck frame.The center percussion mounts were devised for 1969 to 1970 Ford Mustang 250s only. The Fox in line six K member just juts forward 4-1/8", but so do the 300 big six verses Small block 302 Fox mounts. The extra forward stance on the 3.3 liter Fox K member is only to use the 361 FT or 332 FE or 300 big six rubber motor mount isolators....the auto geatboxes sat with the separator plate in the same spot.

[82MoreDoorFox]

FE 332 and six cylinder engine mounts were made to reposition the small block in the F truck frame.The center percussion mounts were devised for 1969 to 1970 Ford Mustang 250s only. The Fox in line six K member just juts forward 4-1/8", but so do the 300 big six verses Small block 302 Fox mounts. The extra forward stance on the 3.3 liter Fox K member is only to use the 361 FT or 332 FE or 300 big six rubber motor mount isolators....the auto geatboxes sat with the separator plate in the same spot.

My method used was due to budget and thinking out of the box. I’m saying he can use it if he likes. Showing him options that he has for less $$ and time. It may not be the best but having the motor 1.5” forward does not do much harm or I can’t feel a difference. I’m sure if it did they would have issues with the extended length of the truck behind the rear axle as compared to a coupe. Very minimal. And this is not on a trailer.

To the OP, sometime you have to do with what you have. I just posted what I did to show what you can do.

Cheers,
Murillo


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[WRusco]

The 300 ci 6 cyl also used the small block bellhousing.

[erratic50]

Stupid part of the 300’s is they also a 4.9L. Barely any displacement difference between the “5.0” SBF and the 300’s

Many of the 300’s are a very heavy cast block. The factory block holds as much as 1000 HP even at high RPM. The bottom ends are stronger due to hardware used to retain the main caps, etc.....

Also many of those old lumps can be bored big time and there is room for more stroke than factory in those mills too. Not sure how much displacement one could carry.

It was a thing of mad scientist proportions to see someone take a pair of 351M/400M/351C heads in and have one cylinder carved off of each then fit the passages with extension tubes epoxied in, etc.... but those brave enough to do that crap were able to get over 600 HP in NA form from a 300 six banger......

Weight wise they aren’t as heavy as a W or C, etc. And yet none of us like, use, or build anything based upon the 300.

I’ve often wondered why. The ones I’ve seen in person then experienced were actually nothing short of absolutely unreal.

Like keep your Supra engine, time to learn where the bear really craps in the woods stuff

The way we pick what we will rework and what we won’t is entertaining if nothing else. A 6 in most instances is also a lot easier to work on.

Anyway ..... sorry for the hijack. Hopefully you’ve gotten some good detail on the W and C6 combo in your car. Good luck - hope you get what you want!

[4eyedblind]

If you've got to go looking for a K, take one out of an 87-93 V8 Mustang. Readily available and, if you get it dressed, it'll have the improved quick ratio GT steering rack. The a arm pivots are further out on this K, so you get far better geometry than with the previous Ks.