My port measures 1.330x2.155 csa would be 2.866. Wallace calculator figures bore and stoke and csa to give limiting port velocity. Mine is 559cfm. How do I use this number to figure proper stoke or piston speed to match my heads. Andy your graph tells me max torque word be 5080, which is close as my peak is actually 5100. I'll check my pipe max program later. I have everything for next build but crank rods pistons.