There really isn't any problem with fuel pumps with the integrated fuel filter. My 460 has one on it. However, I was having fuel delivery problems and finally figured out it was vapor lock. The lower radiator hose was in contact with the fuel filter canister. When the engine warmed up it would cause the fuel in the canister to boil, and no fuel made it to the carb. I had fuel from the tank to the pump, though.
You might check and make sure your fuel lines are clear of radiator hoses and exhaust manifolds, etc. Check for anything that could be causing a vapor lock condition.
Ok so I installed mechanical pump # 3 and also replaced all the rubber lines again just to be safe. I dropped the take made sure the tank was clean again and it was. The only bad thing was the little screen on the sending unit was off because of the air I blew threw the lines to see if they were clear. The sending unit filter was clean though. I also drilled out the gas tank vent and took the little bobber out so I know its breathing good. A new fuel cap was also installed. The truck seems to be running go today so for now she is fixed. I never really figured out what the problem was but it seems to be good for right now.