In your alls opinion what do you think these will give me? Edelbrock Performer 5.0 Aluminum heads. 170cc Intake runners, 60cc combustion chambers, 1.90 intake 1.60 exhaust valves. Springs rated to .575" lift hydraulic. Pedestal style rocker mounts. right now all i have is longtubes and gears. Should i port and polish em before i put em on if i do get em. they are used.