I am wondering what the difference in power loss is between a TH350 VS TH400 S/P? I have a built Buick 350 engine and I have a good working TH350 that I swapped out for a TH400 switchpitch and had Jim Weise build me a 12" converter for it. Would the TH350 with a 3,000 stall converter be a better choice considering the weight and powerloss difference? Thanks Tim
I've always been told that it takes ~22 HP to drive a TH350 and ~40HP to drive a TH400 tranny. Tough to beat the durability of a 400 based tranny......not to mention the dual purpose S/P feature.
I quess it depends on what you want to do. I think the S/P 400 would be nice for the street/strip driving. However the TH350 is plenty strong for even built up 455's, so I don't think you are going to hurt it with a 350. I went 10.79 with a TH350, so I think you will be ok. It does take more power to run the 400, so if you are looking for some more power (we all are) then go with the 350. The thing that kills transmissions is too much heat, so make sure you have a good transmission cooler no matter which one you use.
350 > 400 s/p. That is a very good set up, with extra low gear to go with to 3.08 and bigger tires. Put switch on it so you can control the s/p and you really will surprise the road kill. Diver
