I'm running a 742 case with 5.13, billet caps, spool and Cass's race axles. I've recently back braced it since the tubes were starting to twist.
The alum center is based on the 742 but its just beefier and stronger... it has threw bolts(on 3 of them) to hold the caps which are big... when I bought mine they were reasonable on price and I got 35% off, now days they're pretty pricey
Yup, if I remember right. A lot of strength is gained with the through bolts, even though it's aluminum.
Sorry to hear about rear, jcastle1, don't have any leads for ya for on dana 60 rear ends.
