Fuel Pump and Tank Upgrade

[TheScaryOne]

My fuel pump went out on my SHO, and since it had the 16 gallon, I figure I'll just upgrade to the 18.5 gallon when I change the pump. But I need to know if I just need the tank, or if there is a proper sending unit for the larger tank. Most websites only show one sending unit, is this correct? If I can reuse my current sending unit and pump assembly, I'm just going to get a Walbro. But please, all help is welcome as my car is currently not running!

Thank you!

 

[Storm-Chaser]

A little late, but . . . .


Ford actually lists different tank-specific fuel pumps for each of the three tank sizes (16.0 / 18.6 / 20.9). Unlike GM, I don't believe this is due to the different tanks utilizing differently wired vehicle-harnesses, or tanks in which the fuel pump sits differently within the tank (like GM has).

The 16.0 and 18.6 gallon tanks are essentially the same, with variations in the outline of the shell of the tank allowing for the added 2.6 gallon capacity. The basic dimension of the tank at the mounting point, top-to-bottom, is the same. So while it will fit in there, I don't know if the unit is different because of how it senses fuel in the tank (eg. variable resistance due to fuel density, or variation due to "where" the gas sits in the tank).

The end result, is that it should work, but you may find that fuel gauge is not as accurate.

 

[Phoenix]

The sender Is different , I learned it the hard way.

 

[AREA 91]

I am pretty sure there is a difference in the pump/sending unit between the two tanks.

 

[zak]

Any idea of weight differences between the 16 and 18.5 gallon tanks? I think 18.5 was the standard SHO size (Gen II at least)

I also wonder whether the filler necks are different

zak

 

[Storm-Chaser]

Weight difference in tanks is negligible, and considerably less than the weight difference of the added gas. While I have not seen the 20.9 gallon flex fuel tank, the difference between the 16.0 and 18.6 gallon tanks is in the upper-half of the stamped-steel shell.


:fight:


Basically, F*** "extend/expanded" areas on the top of the gas tank in several spots, to where it more closely conforms to the floor pan above the tank. So it adds minimal weight since it is stamped from the same sheet of steel, as compared to gasoline which weighs ~6.2 pounds per gallon.

Even though I've not "seen" a flex fuel tank, not only is the tank different, but both tank straps and the fuel-filler tube have unique part numbers. For the 16.0 and 18.6 gallon tanks, only the filler tube has different part numbers, but that is based on model year and not (apparently) tank size. For example, 1989 SHO, 1990-91 SHO, 1992-95 w/o flex fuel are the listings I have.