I'm helping a friend out with a 01 1500HD he's working on in his shop.My main question is how important is it that all of the segments in the tune match? I put his VIN into TIS, and I cannot find a base file on the internet that matches his segments. The reason I'm looking for another tune file is his was modified with HPTUNERS, and it is doing some REALLY wierd shifts and were having problems with the fans working properly. So I want to start over with a clean slate to transfer his current custom tune over to, and the tune file on tunefile depot doesn't match the segments that TIS lists for his truck per the VIN. Or would I be that much better off to sit down and copy his custom tune over to an 02 OS and flash that in? He has a custom tune from a well known tuner now that he had me flash in, but we just can't get the trans to shift right into lockup consistently and I want to make sure there weren't changes made with HPtuners that I cannot see.