Kind of a noob question. I have an AP1 with an AP2 motor / tranny. I have a comptech diff housing with 4.56 gears. If I wanted to put a stock diff in, do I use a AP2 diff or AP1 diff?

 

Do AP2. It is stronger. They will both bolt in fine.

 

Lies ^. They will not both bolt in fine. It depends on what flange you have on your drive shaft. You have ap2 motor and tranny but do you have an ap2 driveshaft as well? Axles bolt on fine to ap1/2 diffs but the flange bolt pattern is different. Ap2 rear end is known to hold under pressure better though, go ap2.

 

x2..... driveshaft flanges are ap1/2 specific.... i know the transmission side is, possibly not the diff side??? i know that dont help, but im second guessing myself now...

 

It is pretty easy to know, jack the car up and set it on stands. Make sure the car is secure, be safe!!
Look at the 6 socket head bolts that holds the driveshaft to the diff. If the head is small 6mm it is AP1 and if the head is 8mm it is AP2. Once you determine what you have buy that differential, changing out the flange is a pain if you do not know what you are doing.

Good luck

 

Wow my bad. I thought they were the same.

 

Thanks guys. Looks like it has an AP2 shaft.