I bought a 1982 Datsun 720. The truck wouldn't start and immediately knew the carb was toast. I completely disassembled it, and got it completely cleaned up as the previous owner had put gasket sealant in it, for some reason. Got it all back together, and replaced the float, fuel pump and all fuel lines as they were dry rotted.

Now comes my issue.

I have the float adjusted perfectly as of right now. Fuel SLOWLY enters the bowl. I can get it started, runs for a few moments, then dies. I get out, check the bowl and it's empty. Turn the key to on without starting, fills the bowl SLOWLY, and I can repeat the process. For some reason, the fuel pressure can't keep up with any demand. I have since removed the fuel pressure regulator and allowed the fuel pump to blast at 7 psi +/- when I did have it regulated to around 4-5 psi. Does anyone know of anything I can try? I do see the fuel line that comes up to the carb has a secondary line that splits off from it, but not sure what it does, nor where it goes. PLEASE HELP!

You said you "replaced all the fuel line", did you replace it to the gas tank?! If not, there is another fuel filter between the fuel pump and the gas tank. You can access it thru the rear passenger side wheel-well...

Yes, all fuel lines have been changed all the way to the tank.

I'd probably unhook the fuel line from the carb area and have someone turn the key on while you let it go into a cup, if not a ton is coming out, I'd check the tank and fuel pump, if good volume, check carb line..

Already did. Cant get enough fuel to cone out of that line and I can here bubbling in the tank when the fuel pump is on. Fuel pump is new and replaced a 2nd time just in case the first one was faulty.

Well darn! I would drop the tank (or take the bed off) and check everything! Make sure vent line is clear, and pull everything out of the tank and clean it. If 100% the entire fuel line is clear it's got to be a problem in the tank. Good luck on it!