You did say that both mechanical and electric type gauges were used and they showed the same pressures. So that should eliminate teflon tape problems unless you had a fitting that was obstructed and that fitting was used on all of the gauges up to the last one. Also you could have filled the 1st two gauges with sealant and the stuff was gone for gauge 3. That is why the first two would still show the problem but 3 doesn't.
Is the
oil pressure pickup point near the pump on the front of the motor? The reason I ask is mine was like that on the Cobra motor and I moved it to the rear of the motor just off the rear cam bearing figuring that I wanted to see the pressure at the "far end" of the oiling system not at the pump. It really shouldn't make a difference other than with my dry sump I "Prime" the motor by cranking it until I get 50psi (about 5 seconds) then I pump the gas to get it to fire. Its easier than spinning the Weaver pump with an air rachet.
OK DV put us out of our misery...
Can't wait to hear the answer as I've got my climbing boots sitting here ready to really give myself a "kick"...
Regards,