1973 k10 fitech ultimate LS no fuel

[Mike_The_Grad]

Hey everyone. I swapped 5.3 lm7 with 4l60e into my buddies 73 k10. New everything. Fuel system, hydroboost, cooling system, the works. I also rewired the entire truck with american autowire classic update kit. Truck has power everywhere it needs it. Lights, gauges, fitech handheld works. Throttle position sensor responds in handheld, coolant temperature registers, fuel gauge works. When I crank the engine, fitech handheld shows no rpms. I did upload inital base tune from fitech menu. Hard set with key off. Fuel pump sounds like it's cycling. But there's no fuel pressure. I cracked fuel line at fuel rail nothing. Not even smell of gasoline. Tank is half full. I took return line off at corvette style regulator on frame. Nothing. Blew air back into tank and then rush of gasoline. So I connected it back to regulator. Cranked again. Nothing. No fuel at rail. Power to pump because gauge registers. I can hear the fuel pump cycle. But I don't feel the tank vibrate or anything. New walbro 255 lph in tank pump with spectra sending unit brand new in 1987 r10 fuel tank. Ptfe -6 lines all the way. Any help did i fry the fuel pump? How do I prime the pump even though I've cycled the key 25 times. After reconnecting the fuel return line to the regulator filter, I pulled the pressure line after the regulator filter and bone dry. Cycled key, check it again bone dry. What gives????