375 Transmission

[DeputyDan]

Anyone ever heard of a 375 tranny? Tailshaft seems to be the same as 350 will a 350 tourqe conv work in a 375? Any other considerations when swapping a 350 for a 375 that is the same length?

[RUSHNBOBO]

It all depends on which one you have read below:

THM375B - This trans is identical to the THM350, but is considered a heavier duty transmission.

THM375 - This transmission is a derivative of the THM400 sharing the external appearance of the 400. It'll be marked 375-THM on the bottom of the tailshaft housing. It's a light duty version of the THM400, has ABSOLUTELY NO RELATION to the THM375B, and was found in 1972 to 1976 full-size cars. The Turbo 375 was modified to accept the Turbo 350 driveshaft yoke.

The THM375 and has a long output shaft that mates to the smaller THM350 drive shaft yoke. Internally the clutch packs originally had fewer friction plates. Some "Heavy Duty" THM350s were also designated THM375-B.

[MARKDTN]

I would stay away. It is a strange combination of a TH350 and a TH400. I believe the torque converters do interchange with all 3. There is no aftermarket support. As cheap as you should be able to find TH400 nowadays, that is where I would spend my money. Better yet do a 700R4 swap.

[C20-67_N_MO]

Originally Posted by MARKDTN

I would stay away. It is a strange combination of a TH350 and a TH400. I believe the torque converters do interchange with all 3. There is no aftermarket support. As cheap as you should be able to find TH400 nowadays, that is where I would spend my money. Better yet do a 700R4 swap.

I would have to agree with you on this point.

Stick with a TH350 or 400; or go overdrive with the 700R4.

Good luck

[RUSHNBOBO]

If it's a THM375B, it has no relation to THM400.....they are identical to a THM350 with a few heavier duty parts. All aftermarket parts are compatible.

[LEEVON]

I had one in an '87 swb silverado, factory. It started slipping and when I pulled it nobody would buy it, coudn't even use it for a core. Nothing wrong with the TH400/TH350 tailshaft version from what I understand though.

[RUSHNBOBO]

Originally Posted by LEEVON

I had one in an '87 swb silverado, factory. It started slipping and when I pulled it nobody would buy it, coudn't even use it for a core. Nothing wrong with the TH400/TH350 tailshaft version from what I understand though.

That doesn't surprise me....they probably didn't know what it was