iron heads for a 408?

I have a set of Mopar Performance ported iron heads rated at 275 cfm @.500- .600 lift with a port volume of 166 cc's. How will this relatively small port volume affect power production? Do I need port volume of about 200cc's. The rest of my combo includes: 408 shortblock, 750 Holley, a "junkyard" Eddy RPM intake, 1.5 Comp steel roller rockers, belt driven water pump, 9.1 KB pistons, TTI step headers, Comp 242*/248*@.050, .549/.544 lift hydraulic roller cam, MSD 6AL ignition, 2.5 exhaust,4spd manual, Super Stock springs,9.25 axle with 3.55 gears. I hope to get 450-500 hp. All going into a '71 Duster. Any critiques, comments?