Can you use a different fuel pump other than the one in the tank? I want to eliminate the stock pump and use an external pump so it can be easily replaced when needed.

Thanks in advance

 

I'd use the stock pump. The stock pump (the genuine GM or the AC-Delco "Original Equipment" pump) is quite reliable.

There are many first generation S/T series trucks and SUV's which still have the original, factory installed stock pump. You're wanting to redesign yours for a once every 20 years event? Seems like a waste of effort.

If your pump has failed, there are several things you should do to make sure that the replacement will be as reliable as the original. First, inspect and clean the tank out. If you don't, then whatever trash or contaminants that are in the tank that might have contributed to the failure of the first pump will take out the replacement fairly quickly.

Never let the fuel evaporate/dry out in the tank. Don't let the thing sit for more than a few weeks without starting it and driving it at least 10 miles. Dried up varnish within the fuel pump will lead to an early failure. That will kill any pump.

Never run the thing out of gas, and let the pump suck air. Fuel is the coolant and lube for the moving parts in the pump, and running out of gas is like running your engine with no oil in the crankcase and no coolant in the water jackets. Running the fuel pump dry will kill any fuel pump.

Finally, if you must replace the fuel pump, replace it with a reliable, original equipment, stock replacement pump. That means get it from the dealership (or an online dealership parts department), or get an AC-Delco "Original Equipment" grade replacement. Avoid "lifetime parts" from the major discount chains.

If you insist on getting an external pump, the only ones I know of that can meet the pressure/volume requirements of these engines (I'm guessing you have the "W" in the 8th position of the VIN, for the "maxi-injector" 4.3L V6) would be the ones designed for the old Bosch "Continuous Injection System" used by Mercedes Benz, Porsche, VW and some other European makes.

Those Bosch pumps (the genuine original units for those vehicles, not some of the recent "superseded" part numbers) can meet the pressure and volume requirements. Those pumps will still need an in-tank "lift pump", or you'll need a fuel tank with the outlet on the bottom. The pumps for those systems aren't designed to "suck" fuel from the tank. They are designed to have fuel available to pump, either from a gravity feed from the tank (with the outlet on the bottom), or from a low pressure "lift/pickup pump" in the tank to deliver fuel to the high pressure pump. Even in those systems, recent pumps and "modern" fuels are not always good enough for those cars to run with. I had an early 1980's Volvo turbo wagon here recently that I had to put a GM fuel tank and pump in (with a 60+ PSI AC-Delco "original equipment" fuel pump). Only with the GM high pressure in tank pump in series with the brand new Bosch pump was I able to get the fuel pressure and volume high enough for that engine. I got 4 different brand new, genuine Bosch pumps, and none of the new pumps could meet the flow and pressure specs required by the Volvo specifications.

 

if you keep having to change fuel pumps just cut a access panel in the floor, ive done it on a few off road trucks where it wouldnt hurt the resale. they do sell inline high pressure fuel pumps but i dont know that much about them. a buddy of mine had one in the frame rail in his jeep when he put a 6.0 chevy in it.

im sure theres more to it then just cutting a line and putting it in