I have a 96 502 that started life as a mpi 415 horse motor. But now I have removed the MPI, and put a dart high rise intake, and a hp500 850 and I have emi exhaust on it. It also has roller lifters and a upgraded merc roller cam. I wanna make 500 horse. So what am I going to need to make 500? Im not sure I will even see a difference in MPH over what I have now...I run right at 70 gps now.