what can i expect for performance?

will be great for the highway... bad for fast starts. but it's going to put lots of stress on the tranny/universals/yokes. i broke a yoke once with 323's.

your best bet is to save a little money back so you can get a different rear, you see lots of them for sale on here. if you can get a 3:91:1 or 4.11's or so you can still drive on the street ok, but highway cruising will suck.

hopefully you can find something reasonable, with a suregrip also.

what type of rear axle do you have? dr. diff (Cass) can set you up with stuff you need to change the gears if you have a decent 8 1/4 or 8 3/4 rear. his website is doctordiff.com