I don't remember the hole sizes. I measured each sensor, and made the hole to fit. I cut them out with a hole-saw on a drill press. Both sensors are AEM. The stud is already there; Just use the correct nut and washer. (I used new stainless-steel pieces, but it certainly isn't necessary.) Thanks for the kind words.

 

I just picked up some new AEM gauges and ran my oil pressure sensor in the filter housing. The sensor sits pretty close to the halfshaft but I made sure I zip tied all the wiring so that it doesnt come in contact with it.