Fuel pump advise

[Luvinit]

Having a problem with my carb running out of fuel on anything but a mild acceleration. I have a stock 402 with a new stock rochester, I had to change the stock 3 pipe pump to a 2 pipe because of adding saddle tanks and now running short of fuel. Has anyone run into this problem and found a solution. I'd like to stay with a mechanical pump but might have to go with electric.

[B. W.]

You shouldn't have any issues running a 2 port vs three port. IIRC the earlier BB trucks ran a two port. Try a volume test on your pump & check your tank vent. You may need a new pump.

Side note: my truck has an aux. tank with a three port pump. when I'm on the aux. tank it fills up the main! If the main is full, it runs out the cap! (no, I did not install it)

[randy500]

Your tank switching valve could be partially close or nternally damaged causing blockage. You could also have a cracked fuel line causing suction loss during road vibrations

[Luvinit]

It crossed my mind to double check the suction side for restrictions. The selector valve is new but everything else is 45 years old. I'll try drawing out of a jug first.k

[Luvinit]

I ran directly from the cab tank to the supply line, instead of thru the selector valve. problem gone. I'll have to get bigger lines to reduce the restriction. Thanks for the help.