If you have to choose between the 2 definately the c-4, but if you can swing it an AOD would be better. The c-6 is big and will rob you of HP especially in a mildly built motor, without the benefit of overdrive. C-4s are cheaper to build and properly built will handle all the HP a mild motor can have.
What's the application (daily driver? strip only? street/strip?)? I think a C6 is too big/heavy for either street or strip. AOD's are nice for streeters (as we all know from 71Gold) but would require a few mods. C4 for strip only. IMHO
Are you meaning to put a C4 in it if its only for the strip? Because a C6 won't fit so he's either going to use a C4, AOD or a Manual
Yes, C4 and 4XX gears for strip only small block (specific gear would depend on if running 1/8th mile or 1/4 mile and what diameter tire will be uesd), or a C4 and 2XX or low 3XX gears for highway only. Or an AOD with 4XX gears for a street/strip application or street-only application (again, the specific gear would depend on what size tire is being used). The 4-5 speed is okay for strip but not likely to be as consitant. Unless it's a big block, the C6 is really too heavy for the application (and probably too big as you mentioned - I dunno for sure tho). These are just my own personal preferences. Your (and many others) mileage may vary.
Heck, I'd even run a C4 with a 460... They got bells for that. Ford even made some C4 bells with the BBF pattern.
