So yea, About 6 months ago I did a swap at a local shop and had them rebuild a 4t65e engine. I put it in my 99 GTP and it runs fine, just shifts ultra hard...Sometimes it sticks in 3rd gear when on the highway before doing a late shift into 4th...Ive read that the final drive ratios are different 2.93 hd, 3.29 for non hd...now my question is should I reprogram the ecm for that variable or are there other things that should be set...and also would it be the main computer or the transmission computer (the guy at this one shop said my car had one?)
