EEC Fuel System

[HEAVCHEV3]

Gd Evening I'm having issues with getting the 70 c10 to start inline 6 250 . Truck was born in Cali. so it has the eec venting system I dont know if I have it hooked up correctly. It seems pretty straight forward but not sure.
I have rebuilt carb,blew out all fuel lines,put new rubber fuel lines under bed and from frame rail to gas line to fuel pump.When I remove the gas lines they are dry as a bone under cab and by fuel pump. I have about 4 gallaons of gas in factory fuel tank. If I put gas in carb truck starts up so why am I nt getting gas out of tank fuel sending unit is nt clogged tank has been cleaned as well. I need your help please. Thanks in advance!!