Hello all! I have a TH350 that I think is from 1977. I haven't pulled the transmission out of the car for disassembly yet, but the current diagnosis is that the forward clutch is burned out, as she won't engage in forward gears but will engage in reverse. I have never done a transmission rebuild and there are so many different kits, so I am wandering in the dark a bit here per say and don't want to buy the incorrect kit for my needs. I'm not looking to build a track transmission or anything that will break the bank, but I do want to change as many parts out as I can since I'll have the case open anyways. In short, I'm just looking to have the car drivable and reliably handle the approximately 300hp the engine is outputting.

Any help would be greatly appreciated!

 

Yes indeed, sounds like the forward clutch is bad. Usual cause of that is failure of the lip seals. More common failure is the direct (3rd gear) clutch butt what you have is probably the next most common way they go bad.

300 HP is nothing for that transmission.

Just about any kit will do fine, as long as it has clutches other than GM "smoothies". There's not much magic in "kit" for those unlike some other transmissions. Actually, it's one of the easiest transmissions there is to build. About the only special tool you'll need is a bushing driver, which you can "rent" at local parts stores, or buy at Horror Fright and such.

More important, is how you build it; clutch stackup, etc. Also, what vacuum modulator you use. Use the kind that's a small gold can with a red stripe. NOT a green stripe; NOT a magenta stripe, and DEFINITELY NOT the big black can. The small gold colored one with a RED stripe, ONLY. When you're at the store buying one, there's no good way to "look up" that, and get it right; you gotta open whatever box they hand you and LOOK AT IT. And of course you'll need a new converter.

Get the ATSG manual for it and follow it closely, and you should be good to go. Be VERY CAREFUL about how you assemble the lip seals, they're a bit fragile during the process. Back in the day I always used to use feeler gauges; nowadays there's a "tool" that looks about like a thin flexible CD, which works great.