head casting number 4772576?

BJ, my flow numbers are right on the money what you posted for the W2's, but I am getting around 201-206 for a stock '915' casting w/2.020 valve. Using a bore of 4.100 test tube fixture. What are you using for a radius port entry? I use 3/4' plexi-glass with a 1/2' radius machined for the '1213' Fel- Pro gasket. Some operators use clay but I find it is difficult to get it exactly 'the same' for each pull on the bench. Yes..28" is industry std. Thank you for the flow data you have posted. I do know how much time is involved with all that testing. Lead on BJ. Terry.