I am putting my motor /tranny swap on hold for a while and now i need to find out about the trans that is in the car now.First question is how can i tell the difference between the th350 and the th250 since the pans look just alike on them,this is the original trans that came in the car?Second question is there a way to convert this tranny to work correctly without the computer control hookup that tells it when to shift,etc.

 

Transmission ID: http://www.nastyz28.com/chevy-transm...tification.php
If you have the T350, it would be the T350C with a lockup torque converter. The computer controls the lockup feature, not when to shift.
B&M makes a converter lockup kit (#70244) for the 200C, 200-4R, 350C, TH700-R4/4L60. Or you can hook up a toggle switch to activate lockup, or leave it disconnected and don't use lockup.