We had an old Bolens with a rear tank that didn't feed fuel very well and the vacuum pump died so instead we just got a universal 12v electric pump from an auto supply store. At the input to carb we just put a T and a return line back to the tank. That way once the carb filled it wouldn't just flood since the automotive pump will put out plenty of flow for a GT carb. It worked really well and from that point it became our ditch mowing tractor because it would always feed fuel really well on hills even without a full tank.
Just make sure if you do use an automotive pump to be sure it is for carbureted vehicles as they only run a few psi. If you try to use one designed for fuel injection you will end up having issues.
Edited by cpg, January 23, 2015 - 11:12 PM.