avargas254

I have a 1987 Cutlass with the 307 engine and TH200c tranny.
The tranny went out a week after rebuilding so now I'm gonna toss it to the garbage...
I need huge help on what tranny to swap behind the 307.
I hear the TH350 tranny bolts right in using the same crossmember, driveshaft, etc. but what else is needed for the swap to work??
JEGS has a BOP TH350 that I've been wanting to buy for the longest and it really sucks I can't figure out if the 307 will need any extra mods to make the tranny shift/work properly.
Most of my local shops know nothing about Oldsmobile so some info from you guys would truely be appreciated! Thank you!!!

joe_padavano

The TH200 and TH350 are the same length. This is a bolt-in swap. The only issue is that the TH350 uses a cable kickdown and a vacuum modulator. The TH200 only uses a cable throttle valve. The TV is not the same as the kickdown and might require a different adjustment. The vacuum source for the modulator needs to be manifold vacuum. Yes, it is acceptable to tee into any line that currently sees full manifold vacuum.

Sugar Bear

TH350's come in 3 different overall lengths, you'll need the short tail shaft BOP version to be the same length as the 200. Did this swap decades ago, the install was smooth sailing with good results.

This may be the time for a specific stall speed converter depending upon your plans, other members can help with that selection, I don't have the knowledge about selecting a stall speed.

avargas254

Thank you guys so much for the feedback!! I will go ahead and grab that TH350 and hope for a successful swap!