will the trans out my 98 grand am 2.4, fit my 96 monte carlo LS 3100, they look the freakn same.

Fit yes. Work maybe. They are different models 4T60e vs. 4T40e (or 45e). They are electronic and are controlled by the PCM. I will see if I can find some data to confirm. The 2.4 tranny is weaker than the 60e for sure.

K. It's looking like a no. The smaller unit has an electronicly controlled pressure control solenoid and the 60 does not. Your PCM has no way of running the new tranny. I feel your pain. I have 1 out of 3 60's that work right.