rear end upgrade
 

What can i do to upgrade the rear end of my 77' 280z, i'm just not getting the power from the engine to the wheels. where can i get parts and about how much does it cost, would i have to get a new driveshaft and transmission?

Your 280z already has a R200 diff in it. You could get one from a 82ZX (3.9 gear ratio) to get off the line a little quicker but I think your clutch may be slipping or your engine needs a complete tune. You can get the books you need for your car at MSA- www.zcarparts.com. Learn as much as you can about your car and you can do it yourself.