still having fuel problems with the impala

Hello, I have had problems with my 68 imp getting the fuel to deliver to the carb. I took everything down to change the filter and came to the conclusion that I had evacuated the line when the filter came off. I primed the line with starting fluid and it ran fine, pulling fuel from the tank and everything. Then, I had the car sit for about 3 weeks doing other things and put it all back together and wouldn't you know, no fuel again. The filter, pump, and rubber lines to the tank have been repalced but I had to prime the line again(I didn't mess with the fuel again, it was just sitting). I was tinkering withthe starter, interior and stuff that wasn't even near the fuel delivery route. Any ideas?

Hello, I have had problems with my 68 imp getting the fuel to deliver to the carb. I took everything down to change the filter and came to the conclusion that I had evacuated the line when the filter came off. I primed the line with starting fluid and it ran fine, pulling fuel from the tank and everything. Then, I had the car sit for about 3 weeks doing other things and put it all back together and wouldn't you know, no fuel again. The filter, pump, and rubber lines to the tank have been repalced but I had to prime the line again(I didn't mess with the fuel again, it was just sitting). I was tinkering withthe starter, interior and stuff that wasn't even near the fuel delivery route. Any ideas?
Check vent line from tank.

Your Impala is almost 40. If the tank has never been out and cleaned, I would start there. I know it's no fun pulling the gas tank, but that's where it all begins. Also with great caution try running the car in the driveway with a new piece of hose from the inlet side of the fuel pump into a gallon of gas. This will aleast let you know you are ok from pump to carb. Most problems are the pick-up unit in the tank.