[Keithc8]

Well this depends on wether you try to run them the way they come which does not work very well because it has the valve shrouded. We had to open the chamber up quite a bit around the valve since the design had the valve seat area kind of sunk and did not let the head flow till the valve was opened to about .500 lift. The chamber design we use and CNC into the head comes up to about 88CCs. There is a lot of deck thickness in the head which is good since we needed to get to 68ccs. We had to mill the heads about .100 to get there. This was on the High Riser style head but would be the same on the Medium riser style head as well. Thanks and good luck, Keith Craft