[jerrspud]

I'm trying to diagnose fuel pump problems as well.
Your original question about different pumps doesn't really matter cuz they're all made by the same one company. Carter, Napa, O'Reilly.. they're all just the same pump still made in one factory. I have replaced mine twice.. one was Carter the other was Napa and they both had the same number stamped on the side.

I have the same symptoms as you but.. in my mind it can't be a vapor lock because it was even a cool day, but it sure seems like it..My PSI was showing one to two pounds after the pump. Checked the tank cleaned all the lines move the fuel filter and I still have the same issue.

It might just be all these pumps are garbage, but if you put an electric one on there and you're still having the same issue... Sounds like something else?

Maybe a spacer on the carb will fix the issue? Or at least help? I'm starting to think more and more it is a vapor lock issue in my situation and probably yours.