I have an 85 F250 diesel chassis that is the basis of a project, and I'd like to fit a larger rear tank. I have seen references to a Bronco tank, or a larger aftermarket tank, but what really is the best option?

 

Spectra Premium makes a steel 38 gallon rear tank that is supposed to be a direct replacement, as long as you remove the spare tire carrier.

More Information for SPECTRA PREMIUM/COOLING DEPOT F26C

 

Those are the two obvious choices...

The spectra holds a few more gallons and is easier to mount (direct bolt-in). The draw back is you have to fiddle around and modify the original sending unit from you existing rear tank. Most guys say their tweaked senders are not super accurate.

The Bronco rear tank takes some creativity to mount in the frame. You have to fab some brackets or an additional cross member. However, you can then use (for the bullnose gauge) a 1986 Bronco 302 EFI sending unit. It has the fuel return barb for your diesel return system. All you have to do is delete the in-tank lift pump and run some fuel hose to the bottom of the tank and you're done....

So pick your poison as far as what you want to mess with. I'm going the Bronco tank route just so I can buy a new sender and know that my gauge will work right. Wonky fuel gauges have become a real pet peeve of mine for "reasons"

 

I'll have to think about it for a bit. I have the two tanks, and a 67gallon in bed tank I built, but I'm all for maxing out range. This project has been fabrication intensive, this chassis now has a 71 F250 sitting on it with a later 7.3idi and Zf 5speed powering it. I have a build thread going in the 67-72 forum.

 

One thing that's throwing me off is that 38 gallon is listed as 80-84 only, what is the difference?

 

After that is when they started putting larger sending unit holes in them to accommodate larger senders with electric pumps.