kdeboy said I get the same: LCA = 128 - (((CID/#-of-cylinders)/In-valve-diameter-in-inches) * 0.91) LCA = 128 - (((360/8)/2.02) * 0.91) LCA = 128 - ((45/2.02) * 0.91) LCA = 128 - (22.28 * 0.91) LCA = 128 - 20.27 LCA = 107.73 Close enough to 108 for me. Click to expand...