I have the KE pump upgrade that CP sells, with 1/2" lines, and a big filter my fuel pressure still drops from 6.5 to 3 psi at WOT. I am a little unsure if you get any improvement over stock except for the "bling." The valves in the stock pump bottom and the KE pump look the same to me. I can't really say that the KE pumps are better/worse than stock because I never checked fuel pressure with a stock pump, but it did feed the engine for years without a lean meltdown.

After unscrewing the screws, the diaphram is connected to the base of the pump. With 3psi pressure on my old pump I think the diaphram is shot and needs to be replaced. Just need to know how to change that or the arm.

If the diaphram is bad you will get a lot of gas in the 1/4" vent hose and/or the oil sump for the pump arm ecentric. I have not found a way to get at the pin to remove the diaphram and rod from the arm.

go with a black holley elc pump and be done.

Changed out the pump, no gear oil in the reservoir and the spring under the arm was broke, the other pump was 1/2 full with gear oil. Both now at 8psi. Also ordered 2 Holley blacks, they should be in next week…

Do NOT buy a Holley black electric pump. I had those on my Scarab, One pump a season, after 3 seasons went back to mechanical. No problems now.