are u looking at a 390 kit, where is 5cc or 23cc coming from, piston compression distance? decking the block? I guessed 65 cc heads, 5 cc valve notches pistons, .045" gaskets, 4.100" gasket bores, 3.94" bores, 4.00" stroke , 1.810" comp. distance = a lovely 10.5:1
