I have a 2001 2wd V8 4.8L Chevy Silverado Reg cab, short bed... what is my rear end.

I know its Gm 10 bolt, 8.5", but not sure if its 28,29 or 30 spline...?

 

should be 30 spline..

 

Thats what I thought too... However, I look it up in Summit and in the fitment guide it comes up as "Express 1500" i figured, well hey, it should be the same considering im also a 1500... but Express Van axles, i beleive, are more heavy duty

 

30 spline 8.6. Almost identical to the 89-up 30 psline 8.5 except for the carrier bearing size.

 

Thanks for all the help