ok so I dont understand why you need to put the regulator on the return side would that not make the pressure to the carb be high still please help installing this weekend!?!?!!?

i have the mallory 4309 on order...... just dont understad why!!!
PLEASE HELP the old guys are laughing at me saying im goinmg to catch fire!

You run the send line into the regulator and run the return port into the return line and then run another line from the reg to the carb. You'll need a fuel pressure gauge around, but it's not as complicated as you're making it out to be.

ok still not clear can you make it dummy pro lol just dont wanna f**k it up

You are dropping the fuel pressure to be able to run a carb i think its something like 5-8 psi. A tbi used something like 10-15psi. Your fuel pump (if stock) is still pushing out the same pressure as before your switch. The extra fuel needs somewhere to go that is why you hook it up to the return line.

The typical cheap regulator has an inlet, and an outlet outlet (typically more than one outlet port, but that's irrelevant). It regulates the pressure on the outlet by closing off the inlet when the outlet pressure reaches the set point.

A "return" style regulator has an inlet, an outlet (which goes to the carb, and is often more than one outlet port), and a return. It regulates pressure by restricting the amount of fuel allowed to flow to the return. If pressure on the outlet (to the carb) is high, it allows more fuel to go to the return. If pressure on the outlet (to the carb) is low, it restricts the amount of fuel that goes to the return. It is possible, if the engine is using all of the fuel the pump is putting out, that the return will be completely closed off. Note that the inlet is not restricted, so the flow through the pump will be constant (as long as the outlet pressure to the carb remains sufficient).

Does that help?