Remember,if its 10psi at gauge, one of the first passages from the pump exit, its not going to be that much in the passages in rod journals of the crank at front of the block. My opinion of course."
Its a mechanical gauge. Not a high end gauge, but I swapped it out for another one I had in the shop and it read the same. So I'm guessing the gauge is right. Bearing clearances being a little loose is a possibility. Engine did see the track quiet a bit before I got it.
so, this has got me curious, you mention the gauge will read optimal, because it is on one of the first passages, before pressure drops due to restrictive passages
now, the OP mentions this is a mechanical gauge, this most likely means he is using some 6 feet of 1/8 nylon tubing
would that at all change your perception of difference between oil pressure at the gauge, and oil pressure at say, the #1 main ?