GM-GMC: 87 astro, small block chevy, gm vehicle

Question
my rear end on my 87 astro has gone out
broke 3 teeth on the pinon.....(10 bolt 7.5")
question is.....is there a beefer rear end that i can
install i know that a 12 bolt is better....but from what other
GM vehicle will fit my astro.

thanks  

Answer
Will.   You really dont have to change you diff size. There are lots of aftermarket parts that are great to use in the original 7.5 housing.  Eaton, spicer, locker, auburn just name a few. Most of these companies have parts that are great for drag cars and trucks. p.s. nothing out there really drops in with out serious modification. I have a 88 safari with a lowering kit and a 406 small block chevy 4 spd auto and I'm using a 7.5 diff 373 auburn!