btrbill

Got a 71 Cutlass I bought that has a 455 bolted up to a TH350? I know this is a good tranny, but is it good enough to use with a 455? I have a 350 engine I could drop in but really do not want to.

Thoughts?

(PS... did a search and couldn't find a thread that contains this. If there is one, kindly redirect me there to avoid duplication)

Rickman48

Of course, a 400 would be better, but a 350 w/a shift kit should live a while.

ah64pilot

Bill, it'll live...but keep an eye out for a TH400. It would be a good thing to change it eventually.

btrbill

I actually have a TH400 but I am not sure of its condition. It supposedly came out of a running Vista Cruiser. I have been holding on to it... just in case! LOL

btrbill

Also, if I change it out, do I not need to redo the driveshaft as well?

ah64pilot

If that trans came out of a Vista it is going to have the long tail shaft. You would need to find another one or change the tail shaft out. You will also have to change the yoke to a TH400 yoke and shorten your driveshaft by about 1" (measure first) when switching from TH350 to TH400 short tail.

I just did it yesterday, cost $136 in Humble.

tangokilo

ELY442

I like the low gear on the TH350. Give it a try.

grmchne78

I have had an Advance Auto (Accurate brand) reman TH350 witha shift kit behind my 455 for 4 years, I drive it to an 1/8th mile track and thrash it occasionally and drive it home with no problems. My car is not fast, but runs respectably with consistent 8.40's around 82 mph. If that helps... I would rather keep it that way than go TH400 due to all the (g-body) crossmember mods, driveshaft length changes....