Classic/Antique Car Repair: 1980 Pontiac Trans AM, shop instructor, pontiac trans am

Question
Where can I find the factory measurments for the rear end in a 1980 TA. example: pinion offset, pinion pitch, axle length etc?  I was going to order a new Ford 9" rear for the car and I'm having trouble with the required measurments.
Thanks for your time,
John

Answer
John, I usually go to the dealership and ask the service manager if I can look at a manual for a few minutes. Of course having been the local high school auto shop instructor and most of the dealers having hired my students has helped, but I think that most service managers would help. Or watch the flee markets and swap meets for a factory manual.
Brad