i have an 86 disk brake rear im puttin on my 87 IROC. what is the size of the rear-end? 7.5? 7.62? they are both 10 bolts,i just need to know what size it is so i can put gears and a posi-trac unit in it before it goes into my car,thanx.

 

if it is a 10 bolt, both of those sizes sre correct, GM just changed it for the heck of ot, they are the same size, just so you know, that 86 axle will have 26 spline axles(same as the 87, did not change to 28 spline until late 89/90)