I'll talk to the machine shop who prepped my block. I would like to do this myself, but if if I don't drill the hole straight I am screwed. I might be able to use the cap as a guide, but the drill bit will likely be too large for the hole. The drill required for a 7/16ths 14 tpi helicoil is 29/64ths which is only .0156" larger than the bolt which is slightly smaller than the hole in the cap. I have my fingers crossed that I can use it as a guide, I will measure tommorow.