Return-type and non-return type are different; you can really fuck yourself not knowing which you need.
A return type is a "Gearotor" type pump, similar to an oil or transmission fluid pump. it delivers whatever flow rate you paid for.
Stock is ~86lph, fwIr. The excess returns to the tank. 255lph will turn over the tank in ~5 minutes, ignoring what you would use idling.
Gas is a bad heat conductor, that volume cycling would increase the temp in a tank, but you could heatsink the return line easily, if that was important.
A non return pump is a turbine, with flow proportional to voltage, supplied by a fuel controller.
Like I always say, "Know your pump like you know your pimp"...
Red '96 Cougar XR-7 240k mi. '02 4R70W, PST DS : '03 PI engine, 04 maf, 24lb injectors, 2.5" exhaust, '02 4r70w + Jmod, DirtyD0g TC + cooler + 3/8" lines, 255 walbro fp. Alpine system.
Black '96 Cougar XR-7 (Lazarus) 210k mi PI Intake, '02 4R70W, Jmod, PST DS, GrogTune, Konis, Mark LCA+Poly, racecougar Custom Engine Chain, and JL and racecougar Bracing.
Black '97 Tbird Limited Edition, '02 4R70W, 255 walbro, PST DS, PBR Brakes&SS lines, Toicko Blues & Springs, GrogTune.
I'm not Human enough to be human; but I'm trying to fit in, and I'm learning to fake it.
"Never said Hibbity..." - Brian Williams