fuel filter...where is it?
I had one "pre-pump" I went through 2 edelbrock fuel pumps and 1 holley fuel pump. on the 2nd holley fuel pump, I removed the filter pre-pump and added one post pump.
Never had a problem again.
And yes, the tank needs to be vented. fuel out, air in...otherwise, you create a vacuum, and the pump has to work harder and harder -- like trying to suck beer out of a glass bottle. eventually your tongue gets sucked back into the bottle, or you have to let air in, and the beer gets all foamy. but if you let it pour out slowly so air can get in, then it pours smoothly!!