If the mechanical diapragm ruptures, it can fill your crankcase with gasoline even if you do not have an electric pump. If that is your worry, you need to stick to electric only.

Here's what I'm using on my max wedge car. I'm sure someone will have a million reasons why I shouldn't use this but at least for the time being it works, it's simple, it's quiet and it solves the dry carbs problem. Certainly no good for racing but if you want a 3/8" pump that doesn't require a regulator, this works. Mine is mounted on the frame rail just ahead of the mechanical pump. NAPA Part Number: BSHN69405

http://www.napaonline.com/Search/Detail....+50020+2020014#

i just run the electric..was told back then in the 80's that the mechanical one would not pull the fuel with out any restrictions .... some electrical ones can do that nowadays...check on the electric pump company first...

Here's the NAPA Part Number:

BSHN69405

Here is the NAPA part number:

Fuel Pump - (Electric In-Line Type)
Part Number: BSH 69405
Product Line: Bosch

I have a carter electric pump (not sure which but it doesn't need a regulator). But I found that depending on where the vane stopped I could run up to 50mph before my car would start starving. So I bypassed the mech. pump.

This winter I'm going to run a bypass line with a checkvalve around the electric pump so I can run just the mechanical when I cruise and turn on the electric when I race or need start up fuel.

Car is a 68 charger with a 406 small block.

X2...no issues

Just thinking out loud, wouldn't the mech pump lever need to be in the right position for an elec to push fuel thru it with the eng off so the right valve is at least partly open? No elec exp but if I needed that system either for adequate WOT delivery and or priming the carb I'd get the lo po carter elec mentioned + a mechanical pump up front & if my psi was too high in everyday driving I'd T at the carb inlet & run that bypass to a holley blue reg in series in that line (cap one port) then run it back to the tank & use the reg to adj the return flow to adj the psi at the carb inlet

I've never had a problem priming the carb through the mechanical pump. Maybe I was lucky.

I have the atomic efi on another car and that is exactly how you adjust the psi. Regulator is on the return side of the fuel system.

My GTX has been setup with a Carter electric in the back and a Carter mechanical race pump up front since the late 80's or early 90's.

I tried running just an electric pump and burned them out from all the driving I did and got stranded once or twice. After popping big coin for Mallory's "latest and greatest" pumps and having the brushes fail I went to the dual pump system which has served me well for over 25 years now without fail.

You can cruise at 65-70 without having to kick the rear pump on, watching the O2 gauge you can see when the bowls start to run out when running the speed higher.

Usually passing at high speed ;-)

Nice to get in the car, flip the switch to prime the carbs and then shut it back off and crank it right up.

I suppose you could do a WOT switch but I never got around to it nor have I ever failed to turn on the pump before making a pass.

didn't completely read al of the above so this may have been mentioned but I wouldn't do it. I have seen the electric unknowingly blast the diaphragm in the mechanical and fill the crankcase with gas. very poor lubrication caused engine failure.

1) I have seen mechanical pumps fail all the time back in the day without electrics.

2) Thats why I use a race pump, better diaphragm.

25 year track history with no failure.

You ain`t kidding. I opened a performance holley pump before and that diaphragm looked like it was made out tire rubber. Very thick and stiff.

I run electric + mechanical on two classic PU's to deal with vapor lock... also nice to fill the fuel bowls back up.

The '47 PW is set up on a toggle with a 3/8" brass check valve pump bypass from the HW store so the mechanical pump is not restricted with the electric off. In cool weather, no need for the electric. On hot re-start or temps above about 85 degrees, it won't run without the electric. On this one, I want to keep the OE style integral pump and filter.

On the '78 Ford I added the electric set up to run continuously to solve a fuel delivery problem after adding a bigger tank. On that one I really need to add the oil pressure switch to cut the electric when there is no OP or convert to EFI which is my plan. My wife drove the truck recently and turned the key past off to accessory when she shut it down. That kicked the electric pump on. It sat there running for a couple hours before I walked by and heard it... the fuel pump diaphragm and float needle held. It could have been ugly otherwise.

good info that a race mech is a good idea with its superior diaphram (I'd of never thought of that unless it happened to me & yes that would be disastrous) & if I do that (elec+mech) I'll T at the carb inlet & run it to a holley blue reg & regulate the return flow to control the psi