Hang on a second.
We know you have a 4T60 at the moment. What is it that you are trying to put in?
If you were to swap up to the 4T65, then your pcm would need to be reprogrammed and the correct gear ratio for your new trans could be put into it at that time.
On the wiring. GM was very nice and kept the pinouts the same for the first 7 or so wires on the 4T60 connector and the 4T65 connector. The additional 5 wirres are easy to add by looking at the schematic.
I would suggest someone with a good ability was on hand for the swap. Overall though..I found it very easy.
00 Regal GS: All kinds of cool stuff.