high oil pressure ??

My guess is because you put a high volume oil pump on, hence the high reading. Even if you moved the sending unit, it would still read high.

A high volume pump should operate at similar to stock pressures. My melling HV pump is right at stock pressures. Maybe someone slipped you a high pressure pump? Maybe there is just a problem with the pressure relief valve?

I would think that the only seals that the pump could blow out would be common to the oil rails. For example, I don't see how oil pressure could blow the oil pan gasket (crankcase pressure for sure, but not oil pressure).

Maybe there is a problem with the gauge, wiring or sending unit. I wouldn't overlook those things seeing how the engine was out. My melling runs perfect pressure.

It also could possibly be that your bearing (ie:Rod, and Crank) Clearences are to tight/past spec which at times can cause excessive oil pressure. But I'd start with the simple thing's like Gauge, Sending Unit etc. etc. Try a new Mechanical Gauge and see what you get. In terms of Your Oil Pump a Melling HV should push close to stock pressures.
If they stuck a high press. pump in there I've seen those usually run around 80 at higher RPMs. In your case if your gauge reading is correct and you actually are running oil pressures that high I'd worry about your oil filter being the weak link before the seals. Most aftermarket/jobber filters arent built to handle those kind's of pressure's (Especially Fram...Yikes). Throw on a K&N or Moroso Filter or something similar to be safe until you get to the source of the problem. Those kind of pressure's are tottaly unessasary and do more harm then good. Robs Horsepower and causes a higher oil temperature.

Shon