HELP!!!! Fuel delivery problem

[Highwayman1167]

Hi and thanks for reading
 I have a 1985 C10 Silverado, 305, 4bbl. It had been sitting for about 10 years when I bought it. As usual with any thing that been sitting, I replaced water pump, alternator, fuel pump, fuel tank, and even put on a rebuilt quadrajet. Ok, so heres the problem, when I started it the first time I was amazed. Runs like a champ, good idle, accelerates well, not even any valve guide seal smoke. Got lucky....I thought. It will only run as long as you pour gas in the carb. Very, very little fuel getting to carb, not even enough to feed it.
So far, I have put on another new fuel pump, replaced all rubber lines, blown out the main line from fuel pump to tank and it bubbles loudly in tank.
What's the deal? Is there some kinda valve in the pickup? Why did it blow out well, But it wont flow gas? I'm at a loss and this is my daily driver.

[bd]

Did you check the fuel filter behind the fuel inlet nut of the carburetor?  Make sure it isn't plugged or installed backwards.  And, if an inline fuel filter was added - did you check it?

If the filter(s) are okay, check fuel pump draw (~20" Hg), pressure (5-7 PSI), and volume (~1 qt in 20-25 seconds of cranking).  Unplug the primary power lead from the distributor cap so the engine can't start accidentally.  Make sure nothing can spark.  Be careful of fuel spray and wipe up any spills immediately.  Have an appropriately rated fire extinguisher handy and ready for use.

It's possible the fuel pump pushrod is missing, misaligned along the side of the fuel pump arm, or stuck in the "out" position.

[VileZambonie]

I will add to that by saying check and see if any rubber hoses exist especially around bends. They will collapse and kink