Swapped out the unmodified venturi piece from my salvage pump assembly.
My idle pressure with it is 65psi... So it looks like it was lowered ~5psi from drilling the venturi just to 5/64...but then nothing gained after that (even after I drilled the whole thing accidentally). I think to start, the venturi system was the bottleneck, but not far after the regulator became the bottleneck... I would speculate that I'd need to drill both the venturi piece and the regulator as directed in the Stillen instructions to get a more normal idle pressure.
But as phunk pointed out - my car was tuned with the idle pressure like this.. so I have decided to leave it alone.
Fuel pressure now:
