I've got an 86 F250HD Supercab that when I finally find some free time I'm going to get running and replace my junk 04 Ram 1500...

Anyway it's got factory dual tanks in unknown condition... The truck overall is sound, minus the rust but the PO was a hack. And the truck has sat - so at minimum I was going to remove, inspect and clean.

I have no idea if the senders or the fuel selector works - lines are rusty and will likely be replaced. So changing them isn't an issue.

Since I'm doing bedsides it will be nothing to cover the forward fill hole and delete the mid tank and run a Bronco or aftermarket big tank.

I'm not thinking of many cons...

Truck's going to run a 351w - I've got too much SBF stuff to justify going with a 460 - of which I have zero parts... I have a full GT-40 EFI intake and the though has crossed my mind to go EFI. With dual tanks that means replacing both tanks and upgrading to the later fuel selector - I would assume. With a single tank it's simple and I could even run a frame pump. Although I guess I could keep the 86 setup with a frame pump but where do I send the return.... I'm getting off topic though....

I plan on running 35's (315/75-16) with stock suspension. I don't plan on much offroad and the offroad I do will be simple, easy stuff. So ground clearance isn't an issue. The spare is the only issue I can see. Probably can't keep it under the tank.

The exhaust is going to be a 3" single so that's not an issue either way.

Anyone have tips or can think of any cons?

 

One "con" is the Front tank is the main tank, and the rear was the auxilary on these trucks. 1980-1987. So parts will be less avaliable for the rear tank than the front in the Junk Yard. And you will never find a 1980-1986 left bedside etc with the front tank filler removed etc if needed in future... Never existed Factory etc...

Be better to delete the rear tank if you want the best compatibility with everyone elses trucks.

 

I haz Mig....

I'm putting new full bedsides and painting the truck so if I delete the mid tank I'll close up the filler and no one will know. As for JY parts - I'm planning on simplifying so there's no need for JY parts on the fuel system. New Bronco tank, new sender, new lines up to the mechanical pump... If I decide to go EFI I'll get a 5.0 sender and use something like a mustang 255lph pump in the tank and all I'll have to do is add a return and adapt the hard line to the ford rail. They make AN fittings for that. I'll probably add an inline filter but that's it. The tank and sender are Ford parts and available anywhere. The lines will be universal fuel lines...

That just leaves the bedside. If it's ever hit I'll just repair the bedside and repaint. If I need a new bed I can close up the side and repaint... If for whatever reason I can't do anything and have to run a used bed as is I'll just leave the front filler out. You can open the door but nothing will be there.

If I delete the rear tank I'm stuck with a 19gal tank. This way I get a 32gal tank. Someone makes a 40gal mid tank for the Supercab but it's a poly tank and requires brackets and braces to be made, plus it's not readily available if something happens. Also I believe it uses it's own sender so once again a part that's not readily available.

The only downside that I can see is that I can't run the spare under the bed, but with 35x12.50's planned do I really want to be wrestling that tire up under the bed anyway...

 

If you are just going to run a rear tank, the only things that come to mind are spare tire, but like you said, do you really want to wrestle a 35" tire into there? The other is now you only have one tank.

Welding up the filler hole for the front is no biggie, like you said. Makes exhaust easier (if you ever wanted to put duals on in the future). Possibly less problems in the future, selector switch, valves, lines, etc..

For the sending unit, just use one from a '85 or '86 302 efi truck with rear tank and it'll have the return port in it already, and the gauge will read correctly.

Sounds like you know what you want and have a good plan of attack already. Now, it's just getting it done.

 

Hey, Chop,
How will such a sender read correctly? Any Bronco tank I've seen is ~35 gallons and at least twice as thick as those pancake things on the rear of our trucks, wouldn't the sender need to accommodate that? Like, have twice the travel?

 

He would need one for that specific tank and can't use the '87-up ones as the ohms changed. If he kept with the '86-down variant, the ohms would be correct for the gauge. So, a '85 or '86 larger rear tank with a sending unit for it should work for that application.

In other words, you are correct.


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Edit: I just did some searching and it seems that all the 38 gallon tanks say that the sender needs to be modified, and nobody lists one for that tank. I wonder why this is? Maybe one is still available from Ford? I don't think every factory 38 gallon tank has a modified sender in it!?!?

 

I got the spectre 38 gallon tank from rock auto. They had the best price. It came with everything needed to put the larger capacity tank in.

You have to cut and extend the shaft on the sending unit. I failed miserably at trying to sweat the extension into place. Instead, I used fuel line and put it all back together with the extension in the hose. I am looking for a bronco in the junkyard so that I can get the gas tank skid plate. The tank does hang lower.

This is the modified sending unit.

 

Bronco's are 32 and the aftermarket is 38. The bronco uses the bronco sending unit, not the Fx50 one. The 38 uses the modified Fx50.

Good to know about the ohms - I didn't know that. I just knew that I wanted to go with 2" because I've found both the mechanical and the EFI setups that fit at Bronco Graveyard.

The bronco tank is narrower front to back than the 38 gal tank, so I'm not sure the Bronco skid will fit the 38 gal tank. I have an extra bronco skidplate so going with a 32 vs 38 tank seems better. I can live with 6 less gallons.

Is there any downside to only having one tank? Similar age Chebbies had left and right tanks - it's like the old cars with the fill in the center of the bumper, doesn't matter which side of the pump you pull up to. Since they've both on the same side the only reason I would want two is extra capacity. Right now I have 38gal with dual tanks and like I said, to simplify I'm ok loosing 6 gal.

The only other thing I can think of is that I'm putting ~90lbs behind the rear axle when full vs the 19 gal factory tank.

I just wanted to throw it out there because I really couldn't think of many downsides. It's nice to have a few minds think it over - you never know what you don't think of...

 

I was thinking that I may be able to space the skid lower to cover the deeper tank.

I like having one tank. I also want to run true duals. That side tank uses a ton of space.

 

Yes, the only real downside I could think of, I said earlier about midship tanks being standard. This doesn't seem to bother you so not really a downside.

The other that 81' Chop top mentions can be rectified with the factory optional in-bed spare tire carrier if desired.

Sounds like a good plan. Can't think of much else to say negative about it...

 

First, the problem isn't the depth from what I understand but front to back.

See here - https://www.ford-trucks.com/forums/7...ank-mod-3.html

Stock tank vs Bronco tank. See how much longer front to back the stock tank is. I think the 38 gal tank is the same length.


Also

https://www.ford-trucks.com/forums/7...tank-leak.html

 

I see now. Have to make my own skid plate I guess.