I wonder just how much my d3ve heads that I had on my earlier 460 powered fairlane flowed. All I did to them was remove the egr bumps and had them given a 3 angle valve job. Even with these almost untouched heads this engine pulled my fairlane to a best of 11.98 et at 109.(just wouldn't go any faster) According to formulas this was making about 425 hp at the wheels. Now for the question what do the common heads flow that come on a typical 454 chev like in a pickup or suburban? I have seen them at a swap meet for 50.00 to 75.00 dollars. Real small ports.