It depends on what heads you use. I just did a 4"crank magnum with Mahle pistons, 1.460 compression height, 28cc dish, and 58cc magnum heads, piston .005 in the hole, .027 cometic and it is 9.89. Magnum blocks are about .020 shorter in deck height. If we assume your block us the same then you are looking at 11.3 with 58cchead and piston .046 in the hole, 10.70 with 63cc heads, and if you want a zero deck quench motor it will be about 11.9 with zero deck,.040 gasket and a 63cc head. Building quench at 10-1 with a 4" crank is near impossible with those pistons.