oil press WAY TO HIGH during prime

To the OP.....Yes the original 'shim' is out of orbit. I got a small engine oil pump to go over 100 psi with just a shim of 1/8". That level of pressure will blow the oil filter or it's gasket every time. New pump gears and pump clearances don't need any help to put out plenty of pressure.

Pull out the shim and re-install and then re-prime and see what you get. That is to make sure you did not overcompress the spring or do anything to the valve piston; probably not, but you need to back up and check. 50-70 psi cold is plenty.

Reading that a bit more pressure is beneficial is suspect; taking care that the internal clearances are correct everywhere does far more to put the right amounts of oil everywhere.