Hello fellow JJers. I have been reading this thread for some time and am concerned about the advise given for Triumph oil pressure switches. The problem I see is that some JJers are advising other members to install the wrong type of sender or adapter for an oil pressure gage. First off DO NOT use a tapered thread oil pressure sending unit or a tapered thread adapter for an oil pressure gage. Triumph oil pressure switches are a straight thread, not tapered. If you use a tapered oil pressure switch then there is a good chance you will crack your timing cover. When I was a Triumph mechanic back when the factory was on strike we could not get many parts. Only what was on the shelves at the distributer. Once that supply ran out we had to make due with what we had. I can remember my father taking an American made automotive type sending switch chucking it up in a lathe cutting a shoulder and turning the straight threads.
I hope my advice opens up the doors for discussion so this problem can be corrected.