Having fuel delivery issues

[GMCGrim]

My second new fuel pump is not drawing fuel from the tank. The truck runs just fine pulling gas from a gas can on the floor. I bought the second new pump thinking the first one was bad.

So let's start from the beginning, new gas tank,new sending unit, new short pieces of 3/8 fuel line and rebuilt carb. I have read everything i could find on the subject of fuel pump problems. The lines to the pump are not plugged (I've
checked three times).

So now I am at the point of considering an electric pump or a high quality aftermarket mechanical from Summit or Jegs.

Oh by the way I have done all of this with the gas cap on and off and it doesn't seem to matter. Are the aftermarket pumps any better than the local parts store versions that cost 18-25 dollars.