C-4 vs. C-6

[b3warnick]

I know a little about the AOD and AODE transmissions, but know nothing about the C-4 and C-6.

Which is better for street? Strip? What's the diff.? Which is stronger / more bullet proof ?

Will either one fit a '87 - '93 'stang?

Just tryin' to learn

Thanks

[duplox]

C4s are the C6's little brother. C4s are smaller, lighter, and robs MUCH less horsepower than the c6.
They have the exact same gear ratios(2.46 1st, 1.46 2nd, 1 3rd).
Here are results of a test executed by TCI in July 1991 to find HP losses through a transmission:
Transmission - HP Loss
Powerglide - 18
TH350 - 36
TH400 - 44
Ford C6 - 55-60
Ford C4 - 28
Chrysler A904 - 25
Chrylser 727 - 45

As you can see, the c6 is a brute. It eats horsepower like its paid to. However, it also transmits gobs of torque without complaint. A fresh rebuilt stock c6 could probably take in the high 500s torque for a good ammount of time. As for a race built c6, the sky is the limit. Certainly the brute of the C4/C6 team.
The C4 is third on the list, behind the powerglide and Chrysler A904, and the 'glide is 2-speed. Plenty of places build race c4s for pretty cheap, I paid $750 for one to be built to take 550-600hp on a daily basis. You can go all out and spend 2 grand on a fully rollerized, transbraked, manual shift c4 that'll go 7s in the quarter. C4 is the way to go unless you're broke. Then just throw a c6 in and forget about it.

As for fitting in a fox, I'd think so. You may have to do some grunt work with a BFH on the tunnel in some places. I'm pretty sure they're both smaller than the AOD. It might take some custom crossmember fabrication, but there are probably trans swap crossmembers out there, as I'm sure many many many people drag their foxes with c4s and c6s. They both are available with smallblock bellhousings, so any 289/5.0/351w/351c/400FMX you put in there, it'll bolt up. You can also get a big block bellhousing for the c4(c6s have cast in bellhousings, non-removable, and they're mostly big block bells) if thats your flavor.

[b3warnick]

Hey....thanks for the info.

The reason I am asking is this.

I have a 'stock' '87 5.0 that I am considering modding. Yeah..you read right...'stock', except for a K&N filter and removed the silencer. It's an auto. I am thinking about going with some sort of stroker/crate motor, but still keep it auto. I'm looking at something in the neighborhood of 400-425 HP, hence my question about the c-4/c-6's.

[duplox]

Yeah, for 400-425hp just get a built C4 or AOD. AODs suck about as much power as a c6, but the extra gear is nice for highway cruisin.