Oil pressure trouble
 

I noticed today that the oil pressure gauge dropped to about 15 at idle. It usually sits at 30. If I add some RPM, it moves back up to 65 then back to just under 60. I've parked it until I can get a mechancal gauge on it & rule out faulty stock POS. Could this be the thermowax bypass crap in the front of the eccentric shaft? I remember reading somewhere that the only symptom that would be noticed would be a drop of 10psi or so in oil pressure. Am I on the right track here?

Can't say I have had that problem with the thermo wax thing in the eccentric shaft, but I did as a precautionary measure buy one from Mazdatrix about a year ago. I wrote hoping that when you get a mechanical gauge put on, you would post and tell just how you went about it, gauge name, where you put it etc. I've done the Racing Beat oil filter adapter method in the past and the ...drill and tap a passage in the banjo bolt method. Just curious about other ways to do this.

I was kind of thinking on yanking the stock sending unit & fitting the new sender in it's place. I take it that's not as easy as I think it should be?

Never tried it there myself. I've read post here and there seems to be a matching threads problem. Never tried matching myself, yet.

Kind of figured there might be a thread problem. I figure a brass adapter(s) from the local hardware store may help. The factory sending unit is only connected to the gauge, correct.

Yup.