I measured the fuel flow at the intake of the impulse pump. I have since then remeasured it with a deck angle of only 15+ degrees yielding similar results. The fuel shut-off valve is kinda tiny looking so will check flow before and after then at the outlet of the gascolator where the system goes from 5/16 in to 1/4 rubber tubing for the rest of the way.
I’ve decided to add a Facet non-shutoff pump. Parts on order.
Jon