full groove main bearings oil pressure ?

Here's a very good article:
The Lubrication of Bearings — Principles of the Oil Film and Wedge | NZETC

I think you might be confused about boundary layer lubrication... Internal combustion engines use hydrodynamic lubrication because the oil is the load bearing member and the development of the oil wedge is dependant on the rotational motion. With boundary layer the surfaces are the load bearing members. Least that's how I understand it.
Also in regard to having high indicated pressures... The oil pressure tap is off the lifter galley in smallblock Mopars. If you are pumping a ton of oil into the system, you are not reading what the mains are seeing. You're reading what the lifters are seeing and hoping that this indicates the mains and rods are getting enough. If the passages to the mains are left at factory size, you are not "seeing" the bearing clearance in that reading because you're pumping so much oil into the galley. Pressure is resistance to flow and what it indicates can be doublesided. You have to make sure that the higher indicated pressure isn't resistance caused by passages that are too small or too much of a volume entering the system. Otherwiase you're using a bit of power to make a bunch of heat.
Pressure is pressure no matter where it is read.