If you are going to buy a 12mm 12point buy it in a deep socket. They are impossible to get usually. I tried Acklands, Century Vallen, and every tool and parts store in town and the only place I could get one was from Kingston Ontario. The reason I say buy such a pain in the ass is if you are using ARP main studs. If you are using the ARP main studs you will need a 12mm 12 point deep socket for where the oil pump pickup bolts to the #4 main cap. You have to have it in order to torque it to the correct specs, can't use a box end there. Buy it now, it will save you grief later. Just FYI.