fuel delivery problem

I have a 73 scamp with a 360 4bbl that I'm putting togather.
I has a new fuel tank and sending unit and new fuel lines. I installed a new carter mech. fuel pump and an inline fuel pressure gauge, in the back I have a canister fuel filter above the tank.
I went to start the car and it wanted to start, but would stay running for about a second
the fuel pressure gauge said I had no pressure, I checked for leaks, kinked lines and blew air into them to make sure there were no clogs, I didn't find anything.
the next thing I did was buy a carter electric fuel pump which I installed, I had the same problem no pressure up front. next I put the pressure gauge after the fuel pump the gauge said I only had 2psi. from the pump.
thinking that maybe the fuel filter was restricting the flow I removed it and bypassed it
I have also removed the sending unit to see if the sock was mucked up. it wasn't.
the pump continues to run all the time sometimes dropping to 1psi, sometimes it spins like its pumping no fluid, even though I put 6 gallons of gas in it.
I don't seem to be pumping fuel with either pump any ideas ?100_2521.JPG