in-tank electrical and mechanical pumps. Can I run both? Im using an Edelbrock 750 on a 5.7 sbc. Both are brand new and already installed. The car isnt running yet as im still putting the car back together so i cant test it yet.

 

If you have an in tank pump, then just use it and get a block off plate for the engine. You will probably need an adjustable pressure regulator especially if the car was fuel injected before. If so, it will have a high pressure pump making way too much pressure for a carb.

 

Yes you can use both if the mechanical pump has a return line.

 

Great, thanks! Yes, my mechanical has a return line. Should i run that right to the 5/16 return line that runs to the tank or to the charcoal canister first, then to the return line?

This is my first car project, which has ended up being a frame off restoration and im learning as i go. I was told my brother (whose a Ford guy) that i should replace both, but have read some conflicting information elsewhere. Actually most of what he says isnt completely accurate and i get almost all my help here at TGO through searches and questions.

thanks again!

 

yeah the car was a TBI originally. Will the mechanical pump regulate the fuel pressure or do i still need an adjustable regulator?

Thanks

 

Return goes to the tank.

 

I wouldn't run that mechanical pump at all with an in-tank pump.

I also wouldn't trust the mechanical pump to regulate the fuel pressure. Your best bet is to bypass it completely and get a Mallory 4309 bypass style regulator (bypass = return). Holley also makes a few models that will work.