I currently have a good tune with my returnless fuel system(cobra pumps feeding 4.6L 2V with 2.1KB and 60lb injectors) on my 04 GT. I plan to upgrade to a return fuel system similar to my cobra. Magnafuel 750 with an aeromotive regulator referenced for boost(1:1). I would wire the pump to a relay activated by the FPDM. In the tune, would i just set the pump(fpdm) to run 100% and change the fuel system type(i forget the field name in BE) to return? Assuming I set the base pressure to the current base pressure(39psi) I would think very little tweaking would be necessary in the tune. Am I missing anything?