Mhagie, I get the same results on my gauges. I thought something was wrong because of the mech gauge reading 20# when the oil was hot at idle.
The stk oil gauge was reading the same psi as b4 the rebuild, a hair under 40#. I'm also using a mechanical temp gauge too. It all started when stk engine temp gauge was at 175* and the fan clutch kick in. I knew then, mech gauges were going to be installed. I had a new motor and was getting bad info. GM gauges suck!!!!
92 GMC std cab C2500, Kennedy high flow injectors,port matched, Banks exhaust & gauges, intercooler, 97 cooling, Turbo Master.A means for a Toy