Finally got a seconadry pressure gauge mounted. Couldn't get a hold of a mechanical, seems hard to get in Sweden, but the electrical reads 2-3 bars (30-45 psi) at idle and 6-7 bars (90-100 psi) running.
Still don't know why my stock sending unit sends a low reading. It worked just fine on my old engine???
Just glad it wasn't the main bearings!!!