I put a set of the procomp heads on my engine when they first came out, about 7 years ago. I bought the bare castings and hand ported them myself, intake flowed from my memory about 310cfm @ .700 I bought good valves, springs and retainers. Cam is 7.00 lift 277 duration has 225LB on the seat and around 574 open pressure. I opened them up to max wedge size, and I had no issues with shafts fitting the pedistals. engine is 512 CID and made 725HP car has run a best of 9.64@ 140mph I fresened the engine once four years ago just touchewd up the seats, guides were OK. Engine is due to be freshened this winter, been toying with the idea of having them CC ported to see how much they take off them from what I did. I did little to the chambers. Which shop is the most ressonable for the CC porting?