Hi, my advice,,,,I have a 4-bolt bbc block and wanted to build a blower Rat. Like everyone else I'm limited with toy funds too. I can't afford to buy tons of expensive parts and be disappointed. I'm copying a dyno proven pump gas 830 hp@6400 rpm 496 bbc 8-71 Blown Rat. I'm using same crank, rods, pistons, rings, cam, lifters, heads etc...following their build. The Co that builds these turnkey engines offer a one year warranty too. I called them and asked questions, most of engine specs was on their web page. They build the blower engines with the mindset that a street rod person is buying it. Paying someone to install it and only knows how to put gas in tank and drive...They have been building blown engines since 1989...know what parts work for reliability and hp levels...