Fuel pump blues (i give up).

I've run the holley red pump on the street for about 6 yrs straight,daily driving.
I stopped using it cause I didn't want to hassle with mounting it between the new dual exhaust & frame [it was on a built slant dart before I got the valiant]

I've been running the same stock replacement fuel pump, which puts out about 6 psi, on the 340/410 valiant since 2004.

no issues here, but fwiw I don't run nitrous.

must be relief valve in the fuel pump or something, I don't know...

as for your car slowing down, maybe the drag of that hp fuel pump-drag/hp/mph
ponder gph vs necessary psi.