[Oldsguy]

Well yes, pressure will drop as tolerances loosen up. As I have read, the main and rod bearing tolerances especially determine oil pressure, the tighter the tolerances the higher the oil pressure can be, that makes sense to me. As to how many miles are required to see a significant drop, I can't say. I really wish we could get a response from a machinist/engine builder, that would be the most definitive. I think you have a good idea about trying another guage, is your present gauge direct sensing or remote? The direct sensing guages are the most accurate but then you have to run your oil line into the passenger compartment, it is best to use rigid line in place of the plastic stuff many gauges come with. You probably already have done that. Well, good luck!