I'm thinking about swapping out my 250 straight 6 for a 351 in my 1975 comet. The '75 only has a 3 speed automatic, I was wondering what I should go with for a transmission and where I should even look for a new one. thanks !
Ultimtely it will depend on what you intend to do with the car. A C-4 is a good reliable trans and will fit behind a 351W no problem. An AOD is another good option if you want taller gears and manners for highway cruising...A T-10 4 spd or T-5 5 speed is good too...Its up to you man... They can generally be had used, locally. Or re-manned or hopped up. Check out a couple car magazienes...You will see ads for outfits that build em/sell em. Just check here after you find one,to see what the guys here say about the suppliers, whats a good one or one to stay away from etc...Good luck!!!
Hey thanks a lot man ! That info was actually really helpful, I don't know why I had never thought to look in a car magazine ! Those are literally the only magazines I buy. And a few things I'm concerned about.. The guy I'm getting to put the engine in says a big block absolutely would not fit, now, luckily my new engine happens to be a small block as it turns out, but I've heard that a big block is possible to put in with new engine mounts and a little custom work to the engine bay. Should I be concerned that this guy may not be entirely familiar with what he's doing ? He also suggested that instead of getting a new transmission I just go with a shift kit. Can a 3 speed handle a 351 and overall what size transmission would give me the best performance ?
A BBF will fit with lots of mods... 302s fit just fine...351 takes a little creativity. If the installer isnt familliar with doing a ford engine swap in a mav you may want to do some research for him before he starts so you can tell him the ins and outs. A C4 trans behind a 351 will live just fine as long as its built properly. A C4 from a 6 cyl will need more clutches added to it to put up with the V-8. A V-8 C4 will be happy all by its self. But you still need to first determine what you want/expect from the car before you jump in. Upgrades/mods must be thought out according to what the engine is capable of, how built up it is etc... You need to read through the threads/tech articles and bone up on the particulars before you get into this. All the info can be had right here on the forum regarding engines/tranny and the particulars/ins and outs/do's and donts. Well informed will perform well...Good luck!!!
Okay, so bottom line is, if I leave the existing 3speed transmission in there (i have no idea what type of tranny this is) will I have any problems if I just put a shift kit in with the 351? Thanks for all the help guys.
yes the trans needs more than a shift kit to live behind a 351. it needs the extra clutch disk added wich requires the amout of labor a full rebuild does. so go a head have have all the rebuild parts replaced and or upgraded.
So I'm guessing the guy I originally was considering to commission for the job isn't the right guy if he wasn't able to tell me this.
And not to question your help, because I do appreciate it, but why would my transmission need a new clutch disk with the 351 ? Would I damge the tranny or engine ? Or are we talkin less power ?
The C-4 behind the six has fewer clutches in the clutch packs than a V-8 C-4. It wont take the extra torque for long if you intend to bang on it a bit. Rebuild it and put a Trans-go 40-2 shift kit in it (best one out there) and Alto red clutches...
