A 140 pump with a return/bypass regulator will require a 1/2" or larger return line from the regulator back to the fuel tank. You'll need to either change to a fuel cell or figure out some way to adapt a 1/2" return line to your stock fuel tank.
This is why we developed the PowerSurge units. No need for a large return line back to the tank. A small factory type 1/4" return line works fine.
