fuel pressure dropping over time

Don’t worry too much about it. Leave the port open to atmosphere, set the fuel pressure and run it. K.I.S.S. It not need be overly complicated. And I wouldn’t choose the deadhead style over what you have. Other than for testing of course.
Well, I had it set for 6
Got on it and it dropped to 2, so something ain't right

I agree the return style should be better, that's why I swapped out the deadhead in the first place..
But it seems like a good way to troubleshoot it now