I'm replacing the bolts on the AFC housing with allen-head cap screws. I know the correct sizes and have all "in stock" except the M6x1. 0x16mm for the top two; also don't have any 18mms which would work too. I do have a good supply of 12mms and would like to know if the 12s will be long enough or am I going to have to make a trip to hunt down some 16s? Anybody know? TIA