im getting a 73 nova rear end 8.5, just wanted to know if this is better then the 8.2 3.36 eaton posi 28spline thats in my camaro.i wanna know if i can upgrade the 8.5 to 30spline and will this rear end work in my car?

Yes. Yes. and Yes.

If you advance search "8.5 axles" for posts by "big gear head", you'll find lots of discussion and very nearly a complete parts listing from Freddie, one of our rear axle gurus.

http://www.camaros.net/forums/showthread.php?t=156026&highlight=8.5+axles

The 8.5 can be built much stronger than the 8.2. I recommend a new 30 spline Eaton posi, 30 spline Moser axles and a good installation kit. The gears are up to you. The plug welds on the 8.5 are not very good, so if you plan on beating on this rear end I recommend having the axle tubes fully welded with nickel.