mph vs. powerheads

i know mph flows 550 235 202 .600 237 207 and powerheads flow 228 intake and 208 exhaust. anyone know how much power difference there would be.
mph costs 1800 for bare heads. I can get powerheads for 1800 fully assembled with cams ferrera ss valves, valve job, and 7000 rpm springs.
any input will help.


thanks