An engins is still an engine no matter how you look at it

500 RWHP is a bit much to shoot for. Even some of the BEST dont make it there. 450 is a more realistic goal Like AL said. With a GOOD heads and cam package along with all the bolt on, it shouldnt be a problem. Just very expensive. You will need a new clutch, but you can retain the stock flywheel. Also, with the cats... ditch them. We make better TQ and HP without them because it chokes the exhaust. Also, under the curve is better. Most seem to have the spring thing worked out these days. It was a major problem about a year or so ago with breakages, lost engines, etc..

The Vette is a nice choice. Ive been looking that way myself and getting rid of my car. the 99 FRCs can be had from $20k all the way up to 30k so the are definetly affordable now since its a very tough market for them right now.