Fabricated Aluminum Valve Cover

Moroso Perm-Align gaskets
Strange thing is just got three bleeding oil,all on the bottom.
I pulled the covers,poured a little oil in them and they are not leaking around the top of the tubes at the welds.
Takes about 5 min. for the leaking to start.
Running a HV pump,75psi @ idle hot,15-40 oil.
Am I the only one that thinks that's a lot of oil pressure, hot, at idle no less?