Can 8 1/4" rearends be made into street performance pieces?

depnds on what you mean...how much HP you pushing. I had bee told and now believe that for anything UNDER the 450 HP range and NON racing applications it will work just fine. Ive FIRST HAND seen a guy with a rebuilt(stock rebuild just updating the internals/gears) with a 435 HP(engine dynoed) SB 340 run his for 5 years now without a hitch and that DOES include a few street strip trips(1-3 a year times at the strip NOT weekly) just for fun...his is a 4 speed car also. So take that for what its worth. I dont race so i wont WASTE the $$$ for a 8 3/4 just not worth the extra cost.