Shake rattle and roll

After driving all over town to find parts, I shove an air compressor in the fuel and return line by the pump and routed a hose on the other end into a glass bottle. Flow was great no debris or gunk came out. I replaced the fuel sender screen after cutting it open to add a spring in order to prevent it from getting sucked flat. Cleaned the return valve on the sender. Replaced the fuel lines to the tank and the rubber seal to the sender unit. Fire it up and..... even worse pressure than before 4-5.5 psi but fluctuating like crazy and still dropping with throttle. Im running out of ideas and patience with this one. I guess I can throw another pump at it but the one thats currently on it was working great with the old motor. What am I missing here?

Just for grins, bypass the old metal line and just run a rubber line from the tank to the pump temporarily.
compressed air might have just crammed junk further down the metal line and not cleared it out.
Personally, I'd stick an electric pump on a gas can closer to the engine and see what happens.