The rest of the combo would stay the same. im saying head swap only, what the increase would be, if any.. Its in a 1972 dart swinger. 9.4:1 440(TRW-2355 pistons), 284/484 MP cam installed 4 degrees advanced, Holley street dominator intake with 1050 cfm 4 bbl., 1 7/7 fenderwell headers, electronic ignition at 20 initial, 34 total. The psitons have a compression height of 2 061. and currently bone stock 88cc 452 heads..How much increase would i be looking at by swapping the bone stock 452 heads for bone stock 88cc edelbrock RPM heads?