I picked up an 88 ram w250, carbed 360 fac 2bbl/auto. Im gonna be swapping an 01 carbd 5.9 magnum and havta run an electric pump. Could i use a tbi pump/sending unit in my tank then regulate that w/a return line? Or would i be better off running an inline pump? The plan is to plum new fuel pump to current motor, then do the motor swap trying to break the whole swap into a couple of weekends as this is my daily driver. Any imput would be appreciated.

I assume TBI uses the same 40-50PSI as MPFI? If so, that pressure may make it difficult to connect the fuel line to the regulator. I don't know that a rubber hose and a clamp will hold that kind of pressure

If it will, or if you can fab a more secure line to the regulator, AND a regulator can step 40-50 PSI down to 6...then I'd just run a dead head set-up. No need for a complicated return system on a stock daily driver build.

TBI is around 14psi. Uses the same pump at MPFI. Any FI pump will work as long as the regulator controls the pressure.

Right on, i read in a past thread someone swapping an 88/89 tbi to a carb, member suggested to run current intank setup and regulate it. Unless i misread they were talkin in the teens as far pressure for tbi. I dunno

Gotcha, sounds like I'd be better off to just run a carter or holley red inline.

If you don't need the in tank pump for future EFI, an external low pressure will do just fine. Regulating down is the easy way to use the existing EFI pump.

you can regulate the mpfi setup down to 14 psi. just be sure the regulator has a port for returning the excess fuel, through a restriction orifice. you can send the return line back through the tank vent hose if needed, just be sure to have a vented gas cap.