Hello does anyone know the stock stall speed on a 1970 TH 400 in a 442? Thanks

 

GM doesn’t publish a stall speed number, I’m guessing for safety reasons. The only way to test it is to get on the brakes and throttle hard at the same time. You can imagine the possible damage caused if the throttle sticks, broken motor mounts, cars moving unexpectedly, etc. That and the test itself is difficult to gather useful info due to brake and tire grip.

To answer your question, I would guess around 22-2500 would be in the ballpark

 

Idk. My 455 TH400 has never flashed over 1800 rpm.

 

I would guess the 442 transmission got a converter with a little more stall speed than others. The W-30 cars probably even more. Of course, if the transmission has ever been overhauled the factory converter is probably long gone, who knows what is actually in it.