Which kit?

If your intentions are to race this car seriously, and I mean drag race, the summit kit or the ebay kit is probably are the wrong products to be using.
I would suggest a Wilwood kit or a Strange Engineering kit that use better and lighter components and sell for under $500.
There's alot of better ways of spending $500 than on disc brakes or aluminum driveshafts to make a car go faster IMHO but again its your money.