Fuel System ('93 Bronco fuel tank install)

 

The original plan was to use the M715 stock fuel tank combined with an external high-pressure fuel pump compatible with the Ford fuel-injection system on the 460. I also wanted the capability to add a second fuel tank for greater range than the stock 28-gal. tank would provide with a thirsty 350 HP+ V8.

A stock M715 fuel tank

The stock '92-up Ford truck intank pumps have a cool feature that allows dual tank operation without any special extenal switching valves. In addition to a check valve on the pump outlet, the pump units have an internal valve that closes off the pump's return line when the pump is inactive. As a result, you can plumb two pumps in parallel (outlet-to-outlet, inlet-to-inlet) to the engine and to switch tanks you only need a SPDT switch to choose which pump will be energized. I liked the simplicity of this arrangement vs. using a separate solenoid tank-selector valve (which are also really expensive). So now, the search was on to try to find a stock Ford sender assembly (in-tank pump, lines & lockring) that was approx. 15-1/2" deep (the depth of the M715 tank).

A stock '92-up Bronco fuel tank

As it turns out, '92-up Bronco tanks are this depth. So I went out and bought one, a '93 to be exact. After I got it home I began to examine the Bronco tank and the underside of my M715. The plan was to cut out the lockring in the top of the Bronco tank and then weld it into the top of the stock M715 tank. The more I looked at it, the more appealing it became to just use the Bronco tank as-is and mount it under the bed, aft of rear axle. The Bronco tank is rated to hold 32-gals. of fuel anyway, so the only penalty for this simpler approach is the loss of a little clearance under the bed in the back. Not much really, as you'll soon see. And if I decide later I want more capacity I can always add a second tank!

The Bronco's skidplate/tank support

After taking meaurements, I decided to use the tubular crossmember in the rear of the M715 as the basis for the front tank mount and use some 1x1x0.120wall rect. tubing to support the rear of the tank.

A worm's-eye view under my M715 showing my new tank mounts

 

Here's what it looks like all finished:

 

 

 

 

BACK