My first question is what's wrong with 80#? You've gone to great lengths to achieve
oil pressure to the right places. You're only real concern now would be the possibility of blowing the filter off, but since it is a race variety, that probably would not happen. I agree 80# sounds high, but other than the possibility washing the bearings out if it gets much higher, it probably won't hurt a thing. As you obviously know already, volume is the important factor as long as the pressure is there to supply it.
I'm assuming you have not fired the engine when I said all of the forgoing.
Things to look for could include something as simple as the adapter to block gasket and or how the adapter actually lines up with the
oil holes in the block. Checking this with a gasket might reveal a mismatch. It may fit one side but not the other...meaning it may line up with either the block or the adapter, but not both. If you used silicone for a gasket, it is quite possible that some got into an
oil passage.
Just some thoughts.
Al