I recently got a great deal on a FiTech 600hp system with command center pump a few months ago. I currently have a Demon 750 on a moderately built 402. I have a stock tank, added a return line sending unit, using a Holley gerotor external pump and Holley regulator, regulating fuel pressure to 7psi, with a return line to tank. Im currently looking at fuel injection in tank pumps, Tanks Inc and Aeromotive. Im curious if I can run high pressure fuel injection pump regulated to 7 psi for the Demon carb until I get a chance to install FiTech system. FiTech system will require a lot of install, that I want to wait until the car is more drive-able. I currently have the gas tank out because Im doing bodywork on the rear of the car, and Im about to put in a fresh built 12 bolt rear so Id like to just go ahead and replace the tank with the new fuel injection in tank pump when I button things back up and be done with the rear of the car.