C-4 or C-6 ?????

I'm building up a 302 engine with 351 heads and some internal goodies! Anybody know what the best factory trans for the job is a C-4 or C-6???

Let me know!
Merry Christmas,
TIKI!
<!-- / message -->

 

why not a T5? i vote C4 depending on how much hp your goin to have?

 

Size matters. lol. The C4 is a lot smaller than a C6 if you care.

 

I've abuse many c4's and never had a problem, but it's always been with 300 or less hp.

 

I've always used C4's on my SBF's, They are tough, a lot lighter, zap less power and can take a lot of abuse when built right

 

I'm pretty sure a built C4 can handle up to 400 hp. Also small and lightweight. C6 are known for pulling down the HP a little more than a C4.

 

It depends on what your putting it in. If your building a truck that might see some towing duty, or a big heavy car like a tbird, go with the C6.

Small light car like a coupe or roadster... C4. But I agree that 4 or 5 speed is even better. I prefer the toploader just for the nostalgia and the whine of the gears.

 

If your motor ends up too strong for the stock trans, the C4 can be beefed up to handle the power from any reasonable 302 street motor. As noted above, much smaller, lighter, and more efficient than the C6. With the parts and technology available today, there is hardly any application that I would recommend a C6 behind a 302.

 

An FMX is the only way to go.

 

the c-4 uses less hp to drive than a c6. C-4s have been used behind bbf,385 series. my vote is c-4

 

Absolutely a C4. If your a chassis builder like me the C6 while a good trans is just to big.

 

You forgot to type in J/K.

 

Damn I'm too slow....I totally was gonna throw that out there....(with the J/K though)


Seriously....I've flogged the living hell outta a c4 behind a 475 Hp cleveland...near as I can tell it live for three owners after me (no weight on the vehicle though twas a izuzu pup pickup....)

 

C-4 is a really tough transmission.... alot of bracket racers use them and they can handle the horsepower. They are small and lightweight and fit well in hotrods. I have one in my 33 pickup and ran one with a 2000 rpm stall convertor in my 48 pickup for 15 years......

 

C-4's are used in race cars all the time. 1000HP is not unheard of with one. C-6 is really just more appropriate for heavy vehicle, truck type application.
But I have to ask, if you're doing an auto, why not an AOD? can easily be built to a 500 hp level and the overdrive is the best of both worlds.

 

In OEM situation, say 1970, a C4 would have been used on 289/302, FMX on 351-2V, & the C6 on 351-4V & up. 302 factory rating about 200 HP & the 351-2V around 250. By '79 351Ws had C4s & low HP. If you spend enough money a C4 can live behind almost any engine, but on a practicle basis it should be adequate in stock form for a 302 unless really built up.

 

Depends on what you have on hand. If what you have to work with is a C6 then go with it, if it's a C4 same deal. To say one is better than the other... it all depends on the situation. The C4 and C6 are great transmissions in my opinion the C4 is better than the TH350. You can't go wrong with a 4 speed toploader... Tough as nails.

 

What car? how heavy? streetcar? racecar? rear gear ratio?

 

I agree with mrpowderkeg. If you already have a good one of either trans, use it. I seem to find the small block C6's in 70's era trucks, probably for towing or hauling a heavy load.

 

Maybe this will answer your question? This a 900 hp 585 ci Cammer with a C4

http://www.youtube.com/watch?v=oDJ_ZMP6JCo

Or how about a NHRA C/SA Stock Class 428 CJ Mustang with a C4, owned by a good friend of mine?

http://www.youtube.com/watch?v=ueRRetb7Q1k

 

BTW, a 302 with 351W heads will only be about 8.5:1 CR, unless you use popups. AFR 165's World 185's with the 53 cc chamber are a better choice. They will get you up to about 10:1.

 

I've had a $50.00 C-4 that "needed a rebuild" when I got it, in my truck since 2000, and it's still going strong. It's been behind a stock '73 302 with a two barrel, a slightly beefed '86 302 with a four barrel, and now a more than slightly beefed 351W with a four barrel. It finally seems like it might be getting a little tired. The shift from second to third is a little slow, and the fluid is beginning to smell a little burnt. Other than that, it has handled everything I could throw at it. Plans are to go with a T-5 in the spring. Anyone need a C-4? I'd let it go for real cheap. How's 50 bucks sound?

 

Don't want to steal this thread but what do i need if switching from a c6 to c4? (1980 302) torque converter, flexplate?

 

You didn't mention what car you are putting this in or how much "modification" you are going to do with the little 302, but a moderately built C4 can easily handle 400/500HP street car. I have a brand new PA C4 street fighter that will handle 450HP and have seen C4's behind cars making more than 900HP. The only thing you need to make a C4 live above 500HP is A LOT OF MONEY.
In my 70 Maverick drag car (408 stroker 351/690HP dyno'd) I use a Mike's racing Powerglide........but that is race only.

IMHO

 

I intended to finish my truck with a AOD. I had one installed in my channeled truck. It made me think "how am I going to be able to drive this thing" (gas pedal design, brake pedal design, trans tunnel, room for me, etc.). I didn't finish my truck before I sold it. I sold it and the buyer installed a C4. If size is a factor the C4 is the way to go. By comparison, that AOD was HUGE.

I used to have a '56 Victoria with a built 292/312 and a toploader 4 speed. I could dump the clutch at 6300 RPM and be gone - all day long.

What car are you referring to?

 

I must be the unlucky one. I used up three c-4's, by towing mostly ,behind a 302, went to a c-6 and never looked back

 

right on. The c-6 takes more power away. Unless it's going to have a bunch of horsepower i would run the c-4.

 

Ok. The Ford c4 transmission came out in 1964 and the c6 transmission came out in 1966. Both transmissions are verry close in design but the c6 has over-drive. The c6 also has a longer exrtension housing. I believe for this aplication the c4 would be the way to go. The aod or automatic over drive transmission has also been built for high performance aplications but I like the c4 more. They make all kinds of performance parts for both transmissions it's up to you and what you want to do. I build transmissions and if you have any questions send me a message on my profile. The Theo has spoken.

 

The C-6 does NOT have overdrive. Both are a simpson design 3 speed planetary trans. The c-6 is bigger and heavier both in size and h/p ability. That said a c-4 can take lots of abuse if built properly ans still not rob the horsepower tht a c-6 does.

 

I'm running a C4 from TCI in my coupe hooked to a 347 stroker and have no problems, Id go with the C4.

Rocky