Reg you NEED to measure each and every one of your pistons deck heights, none of that about a half mm stuff! Get precise!!! I can tell you right now that the max deck height on these motors is +.010, if you truly have a half a mm then you have +.020 and you also have TROUBLE. Going by what you have said so far your crank grinder has offset ground at least 1 of your journals, this is NOT good. Measure every piston deck height and post results, we'll figure it out.