What are you looking for for gains? Nothing's cheap and easy really. You can do headers with full 3" exhaust, LS1/LS6 intake manifold, CAI intake, Cam, RRs, Heads, Lifters, the list goes on. The easiest way to get to 300whp is with full 3" exhaust, LS6 intake manifold, and a pair of RR's (excluding bottle feeding it or blowing it). So good luck to you man.