Wiring priming fuel pump

The Airtex Pump E8012S linked works for carburetors (8 psig max) and isn't pricey. Don't rely on a similar-looking EFI pump since those are positive displacement so will output >100 psig (or stall) without an outlet pressure regulator (all EFI systems have). That high pressure would force the carb needle open to overflow the bowl (dangerous). The little cubic rattle-pump linked also works.

A heavy-duty direct switch will work if rated for the pump current (no spec for Airtex?). The push-button seems best since no chance you will accidentally leave it on, though there are SPST toggle switches with one spring-loaded position. I might mount it underhood near the battery, since perhaps only used after sitting for months. To stay on in a roadside emergency, you might stash a jumper (easiest w/ Packard 56 spade terminals). "Might work" to plumb in series with the mechanical pump, or perhaps plumb parallel if the e-pump has an internal check valve (likely) like the mechanical pump.

For those running an e-pump full-time with carb, safest to install a 1970's Chevy oil pressure switch with 3 terminals: P = to pump, S = starter relay so pump runs while cranking, I = ignition so pump runs off IGN power as long as oil pressure is sufficient (>5 psig?). That will shut off the fuel pump if engine dies (no oil pressure). In my A's, I wired the dash oil warning lamp to "P" so that lamp lights when the pump is unpowered. Since my "P" routes to a relay coil, I use an LED dash bulb which doesn't pass enough current to actuate the relay. Not needed if you have EFI since those systems control the fuel pump, running it for 2 sec on initial power-up to pressurize the system, then actuates again once the engine is turning (per tach signal from spark coil). My two A's have a carb and high-pressure e-pump, for future EFI. To work with a carb, I routed the pump output back to the tank, which builds ~10 psig from just the pressure drop thru the 1/4" level sender stub. I then have an inline pressure reg to reduce to 5 psig at carb inlet. With later EFI, that allows swapping back to a carb with a quick underhood replumbing as roadside fix. Yes, I try to be ready for the zombie apocolypse, or at least avoid a $500 tow fee.