Dropping Fuel Pressure

1983 Camaro with a semi built 350 c.i. Demon 600, mechanical fuel pump. Here's the deaL, after about 15 minutes of running, my fuel pressure goes from 6 lbs to 0 lbs.
I have boiled the tank. Re-routed the fuel line around the header. Installed a clear fuel filter so I can watch it empty. 3 different mechanical pumps. 1 Carter, 1 Edelbrock and 1 Holley. :banghead: I have ran a fuel line from the fuel pump straight to a can of gas, still no pressure after the car ran for 15 minutes. Help me.

Carb must not be set up right and she's dumping all the gas. Should smell richas a pig too.

Also for the giggles, make sure the mount bolts didn't start walk'n on you.