Ok guys, we have all seen the small 1 5/8 mechanical fuel pressure gauges that go on the shrader valve or FPR. I was wondering if it would be possible to use that same gauge for oil pressure. I was going to drill and tap one of the flat surfaces of the hex tube that the oil pressure sending unit mounts on for a mechaical gauge. No one makes one for oil the size of the small FP gauges so I thouht I would just us one of them. Both style guages go to 100 psi so I thought why not? Any input.