Gas tank?
I used a new stock tank and modified a new sending unit to hold a Deutschwerks pump and 3/8" return line. This feeds fuel up to a front mounted surge tank at near 0 psi. It just free flows through the surge tank and back to the tank though 2 Permacool fuel/water trap filters and the surge tank.
A second fuel pump mounted inside the surge tank feeds the fuel rails and bypasses the unused fuel back into the surge tank.
This set-up will feed the motor air free fuel all the way down to the last gallon or two even at the strip or on a road course.