If you weld the spiders...and do it right!...you've eliminated most of the problems associated with that rear. The next weak link is going to be the cap bolt bosses on the pass. side of the ring gear. You could drill them deeper...I'd say 3/4 of an inch, and replace the bolts with longer studs. You could also brace the center of the cap with a nut and bolt through the back cover. Do all that, and I would not hesitate to use that rear in any mid weight, auto trans 12 second car.