When I bought my Roadrunner with a 383 4bbl mostly stock the previous owner put a electric pump on the frame by tank feed it to the mech pump than thru a regulator then to carb runs fine just wanted to know if anybody runs their the same way, Thanks Bob

If it runs fine then that's good but IMO two pumps are not needed. I would probably run just the electric and remove the mech pump. My fear is the mech pump diaphragm may eventually burst then the electric fills the crankcase with gas. I don't think that's very likely to happen but it could...

Agree. As DT said above, I've heard the same admonition against using both due to the failed diaphragm safety issue.

Plus, removing the mechanical-pump slightly reduces HP loss from mechanically driving the pump.

That is how my '71 Charger is set up (electric pump / block-off plate on engine block.)

That said, I have also seen advice, including Holley & Factory "Mopar Performance" advice, to use both pumps together.

Piston Aircraft engines often use both mechanical and electric fuel pumps, in series.

How about just using the electrical pump to start the motor then turn it off when the car is running.

You could use the electric pump in that way as a Boost Pump (for Starting or at the Track.)

Depends on why you want or need an elecric pump in the first place.

Is it a higher volume / higher pressure replacement for a mechanical pump?

You may need more volume or pressure than a mechanical pump can deliver.

Example: Fuel Injection requires higher pressure than most automotive mechanical diaphragm pumps can deliver.

1000 HP engines require more volume than the mechanical pump can deliver.

Removing the mechanical pump means the engine doesn't waste HP driving the pump off the camshaft (though it does use battery / alternator power.)

I was going to install a carter electric pump as a boost pump for the track and when the car sits a while and needs the bowls filled. I will have a switch under the dash for it.

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I was going to install a carter electric pump as a boost pump for the track and when the car sits a while and needs the bowls filled. I will have a switch under the dash for it.

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That's what I'm going to do when ever I get around to it.

I tried this set up with a Holley blue pump and a Carter street/strip mech pump with a switch to turn on the electric pump when I was gonna use the nitrous. After a very short time the diaphragm in the Carter ruptured and and it started spraying fuel all over my headers. I got very lucky that I caught it before I made the pass(smelled it during the burnout) I don't recommend it!!

On a basically stock street car with stock fuel lines, the electric pump shouldn't be necessary; on a car with 1/2" fuel line it's the only way to keep the line to the mech pump pressurized. My Hemi RR is that way, with a regulator, and it hasn't been a problem since building it in 1990.

I don't want to hear the electric run all the time and I have heard that many electrics won't tolerate low flow (like idling) for very long. So I run both mech and electric, but I have a micro-switch on the carb secondaries to activate the electric at WOT and I have a switch under the dash to switch on the electric should the need arise. I have ran this way for years.