If the tank fits, why not?
Don't power the pump from the petcock wires, they are alive at a different time, the pump is powered from the relay along with the ignition coils.
Take the pump, filter and the pressure regulator off along with the return line, I believe the internal pump already has these, you must have the hoses that came with the tank.
Have you considered sealing the leaky tank with one of the tank liner products?