Thanks for the info guys, now which one of these is correct for my car, they are all listed as fitting 2000 GTP, I don't want to order the wrong one:
http://www.ebay.com/itm/4T65E-34T-DI...da1aac&vxp=mtr
http://www.ebay.com/itm/4T65E-38T-DI...9dd951&vxp=mtr
http://www.ebay.com/itm/4T65E-42T-DI...daa534&vxp=mtr
Here is the axle that oriles gave me:
Outboard Joint Type: Spline Nut SKU: STK:GM-8097 OB Spline Count: 33 Brand: SurTrack OB Nut Size (mm): 33 Manufacturer Part Number: GM-8097 Number of Outboard Splines: 33 Number Of Inboard Splines: 39 UPC: 00844084030979 Measurement Type: Compressed Thread Pitch (mm): 2 Location: Front Passenger Overall Length (mm): 620 Length (mm): 620mm