I will give you an example. The best ported 351 Windsor castings will be 60 to 70 HP LESS than an out of the box AFR 165 Alumuinum CNC ported head. Unless you just want to do the work for fun--- dont waste your time, The flow numbers the other guys are talking about are NOT the only thing that makes horsepower. They just dont know that.

JOE SHERMAN RACING ENGINES