IMHO i would check out toyota rears in trucks or early supras (supras are the best) and the truck rears are the same bolt patten as a chevy truck. we used them in race cars so gears are readily avalible, and they are set up like a 9" so you can change gears quickly.. they are also said to be as strong as a 3/4 ton truck rear, so you can really beat on them..

Harmon