proper oil presure?
Do you have a good expensive oil pressure gage? You will need one to accurately keep track of the engine oil pressure. What viscosity oil are your running? I run 10w 50w racing oil. You get what you pay for. I also only run a stock oil pump, never gave me any problems on any of my rebuilt or race engines. The 35-40 psi oil pressure should be fine. You are right, as the engine oil gets hotter the pressure will drop some, that is nothing to worry about. If you are concerned get an oil pressure cutoff and install it to kill th ignition if the oil pressure drops to a dangerous level.