Ok everyone knows the basic TH350s TH400s etc. What exactly is different from them toa TH375 or TH425 models, higher load capacity? Or could it be different ratios?..... I amcurious in what is what here for the GM Turbo Hydromatic tranmission models.

 

THM425,325, & 325-4L are front wheel drive. They do have a higher torque capacity because an extra clutch plate(s) compared to their RWD counter part. With the RWD THM 400 has a 2.48 or THM 350/375B(CHEVY TRUCK) has a 2.52; 1st gears those are what they have and thats it. In the aftermarket, there are custom ratios available. In the FWD, the diff is not part of trans so final drive, if you have the the money, can be almost any ratio you want.THM 375 was a light duty THM400 mostly found in low HP big blocks during the mid-late sixties.

 

Could there be any internal interchangeability between a TH350 and a TH400? This would be nice to know if I ever build a kustom spectator drag car for the oval track we race at [sm=badbadbad.gif]

 

Parts are not interchangeable between THM 400/425 and THM 35O/325. For racing the 2 speed Powerglide is my choice drag or oval. Its lighter, takes less HP to run in high gear, and there is a ton of performance parts available.

 

Yeah, thats a bummer they cant be interchanged lol it would kinda like the "ghost" performance you could say since the normal "motorhead" doesn't go this far into the box for secrets. I should have kept the TH400 I bought for 20 bucks in highschool. Woulda been fun modding it.

Yeah, I think the local Hobby-stock and Thunder car divisions can use powerglides or manual transmissions for oval track. I haven't stepped into the drag strip yet, soon though [sm=lildevil.gif].

 

If you stumble in to a 6 cyl. Glide its the one you want. Also there was a BOP Powerglide, which could be used on Cadillac big block if beefed up, found in some early 70s Pontiac Venturas and Tempests with V8, shift indicator would have PRNDL not PRNDSL

 

Thats kool, and quite interesting. [sm=thanx.gif]