can't put a bearing on the rod of the 160 so no need for a hard pin. I do use a lathe to do the crank and rod and make my carb adapters in the cnc mill and lathe. I made the adapter for the carb which is a wt but don't remember the # off hand , I have plenty in the trailer to get the # and will later. The head doesn't have enough beef for the 10mm plug so the 1/4 x 32 is used.