fresh engine blowing oil filter o ring on start up

I am using a fram ph16 short filter because of the engine to transmission braces. I have run this filter on other la engines with no problem. The oil pump is a melling high voluem pump that I took off of the old motor. It only had a thousand miles on it an ran about 50 lbs pressure after warming up.I,m stumped guys I need some suggestions. This is a fresh motor. it was vatted and all the cam bearings were installed by a machine shop. they were all lined up over a oil hole.

Thanks big block