Need help figuring out aux fuel tank

[H20 Toie]

As much as i love the Square body dually it has a couple of short comings and the biggest issue with towing is range, i can count on max of 100 miles per tank, thats fine for going to havasu but i want to go to LOTO this year so need to figure something out, i want a tank under the bed cover, be nice if i could just hook something up and fill and run off of that tank but not sure if its possible, my system uses a return line so not like i can just run one feed. if anyone has suggestions on a shop i would appreciate it,
Changing out the stock tanks to bigger ones is also not an option since i'm not going to get rid of the power steps that just clear the factory tanks

 

[4Waters]

Find a 6.2 or 6.5 diesel square body and cummins swap it

 

[monkeyswrench]

Gravity flow bed tank, "Transflow" maybe? On my old dually I cheaped out, ran a tank in the bed, an electric fuel pump, and a twist timer from a toy hauler so it would shut off if I forgot...which was common.

 

[Good Stuff]

I’m not sure if I have ever seen an aux tank plumbed into the fuel tank on a gas truck. Maybe it’s fine and just not a common thing. Have seen plenty of bed mount tanks with gasoline and a pump nozzle on them though.

 

[Good Stuff]

One of my buddies plumbed into the filler neck air vent line with a T and put a shutoff valve on the base of the bed tank for his diesel and would just open it up when he hit a half tank and then close it back off when he got close to full tank while he was driving. Keeps you from having to mess with the larger fill hose that way.

 

[Sharky]

Do you carry a spare in the OEM position - back by the rear bumper between the frame rails?

If not or re-locating the spare is a possibility.

The G30 van chassis came with an optional 40 gallon tank that fits back there.

 

[H20 Toie]

Do you carry a spare in the OEM position - back by the rear bumper between the frame rails?

If not or re-locating the spare is a possibility.

The G30 van chassis came with an optional 40 gallon tank that fits back there.

yes that is an option, spare is in the bed of the truck, i know that there is a way to mount the suburban 40 gal tank there, but hooking it up is the issue, usually they delete the dual tanks and run the single in the back. Tank just told me about a place called Tank it in havasu, i'm going to check with them to see if they have a solution, it would be great to keep the bed clear,

 

[H20 Toie]

Gravity flow bed tank, "Transflow" maybe? On my old dually I cheaped out, ran a tank in the bed, an electric fuel pump, and a twist timer from a toy hauler so it would shut off if I forgot...which was common.

yeah i'm pretty sure i would forget at some point

 

[rivermobster]

Find a 6.2 or 6.5 diesel square body and cummins swap it

Yep.

If you're gonna keep this truck, just bite the bullet and do this.

My gas truck would go exactly ONE hour on one tank of gas towing.

At today's gas prices? This swap will pay for itself in short order.

Fuck gas.

 

[mjc]

Do you have factory dual tanks? May a way to use a 2nd factory switch.

 

[4Waters]

Yep.

If you're gonna keep this truck, just bite the bullet and do this.

My gas truck would go exactly ONE hour on one tank of gas towing.

At today's gas prices? This swap will pay for itself in short order.

Fuck gas.

If he could keep the saddle tanks and add the factory 40gal in the rear he would have a 1000 mile range, maybe 750 towing

 

[rivermobster]

If he could keep the saddle tanks and add the factory 40gal in the rear he would have a 1000 mile range, maybe 750 towing

My 7.3 has a roughly 500 plus mile range.

Did I mention, fuck gas?

 

[Good Stuff]

220 gallons should do the trick.

 

[H20 Toie]

If he could keep the saddle tanks and add the factory 40gal in the rear he would have a 1000 mile range, maybe 750 towing

More like 400 towing, i got 6mpg towing but now that i have the long tube headers and fixed the two fried spark plug wires hopefully it goes up

 

[Gelcoater]

More like 400 towing, i got 6mpg towing but now that i have the long tube headers and fixed the two fried spark plug wires hopefully it goes up

What gearing is in it?

 

[H20 Toie]

What gearing is in it?

Probably 4:56 possibly 4:10
454 with turbo 400
3000 rpm is 70 mph
i think they are 33" tires but could be 35's

 

[Gelcoater]

Probably 456

Will it pull overdrive towing?
Or stuck in 3rd?


Edit.... a 400, for some reason I thought it had an OD trans.

Might consider one, or the Gear Vendor auxiliary OD.

And, since it’s easy to spend other people’s money.
Maybe get one of these too.

I know it will fit under the hood of a 2wd version of that truck.

 

[DRYHEAT]

You could always check out KSH they’ve been in town a long time also. Haven’t heard a bad thing about Tank It or KSH.

KSH Fuel Products - Custom tanks, storage, and more

Maximize Your Truck’s Range & Storage | KSH In-Bed Fuel Tanks & Toolboxes Extend your adventures & keep gear organized. Custom fit, budget-friendly!

kshmarine.com

 

[NicPaus]

Should have 410 gears.
I had a 89 with 454 400. It got 5mpg towing. Until I installed the Edelbrock multiport injection kit. Then it got 7mpg.

 

[H20 Toie]

So i did the math and if the tires are 35" i have 4:56 gears
if the tires are 33" i have 4:10 gears
When i pick up the truck from the shop ill measure the tires

 

[4Waters]

More like 400 towing, i got 6mpg towing but now that i have the long tube headers and fixed the two fried spark plug wires hopefully it goes up

If you did a cummins swap you'd get 1k and 750 towing

 

[monkeyswrench]

If we're swapping parts and spending other people's money, why not an LQ9 LS swap? Factory 350hp and 375-390ftlb. Put an 80 behind it (electronic 400 with overdrive) and double the mileage. Parts are cheap anywhere, and then efi to help with detonation on hills, and mixture through altitude changes.

 

[monkeyswrench]

If you did a cummins swap you'd get 1k and 750 towing

There's a P-pump truck with a fresh trans out here for 5k. Truck needs paint, and it's a 2wd, but complete donor

 

[Lumpy]

Find a 6.2 or 6.5 diesel square body and cummins swap it

Actually Dan has the perfect platform for this…I was about to do the same thing to the same truck about 12 years ago. Literally had the same truck give or take a year but no matter. Per California you can swap a cummins 12valve into a gas truck as long as the engine is newer than the truck, hence 1990 with a 1991 engine etc. but you will need to ref it or register in a different state. I had a 1990 CC Dually 4X4 and was about to put a P Pump 12 valve in but found out I was getting a divorce. Did all the research and had everything I needed. Your looking at a Truck, 12 Valve, Conversion front engine mount cross bar, Dodge trans (auto or Manual / Transfer case to marry up the the engine, custom trans/transfer case mounts and modified drive lines for length. Sounds like a lot but its all pretty straight forward. As for the tanks to extend the miles…child’s play. Im running a 60 gallon auxiliary tank in the bed of my F250. Running from Pismo Beach to Havasu, Mead or Shast its a must…hell I towed my 270 over 6000 miles last year. Run a line from auxiliary tank to filler neck with a shut off valve…open valve and go till ya gotta piss.

 

[1tonfun]

Years ago on my old gasser, I added an in bed fuel tank, got an inline fuel pump similar to this clicky and used a GM dual tank switch as an on/off valve clicky wired it up so when you turned on the pump it would switch the selector valve and allow the fuel to flow. When you turned off the pump, the selector valve would go back to the other port that was blocked off. The dual tank valve acted like an on off valve so fuel wouldn't gravity flow.

 

[dp70]

Tank It in Havasu can build you a tank 928-505-2030

 

[575cat]

Do you carry a spare in the OEM position - back by the rear bumper between the frame rails?

If not or re-locating the spare is a possibility.

The G30 van chassis came with an optional 40 gallon tank that fits back there.

Remember the pinto , BOOM !!!!!!!!! , transferflow , pumps into the filler neck as needed , a line from the boat haven,t you watched Roadkill

 

[monkeyswrench]

Remember the pinto , BOOM !!!!!!!!! , transferflow , pumps into the filler neck as needed , a line from the boat haven,t you watched Roadkill

Every Suburban in that Era had a big tank in back. Then they switched to duals with a BCM that transfers from the rear tank, so it seems like a single. With the Excursion's, a single plastic 38 gallon tank.
In Dan's case, the rear tank would be near 5ft in the air. If he gets hit by something big enough to rupture it, he's already had a really bad day

 

[Long Way Home]

Maybe I’m lazy, but, but I would look into renting a new 1 ton truck for those long haul trips, peace of mind, knowing that everything is new without modifying an old Chevy truck, just my two cents. Last time I checked enterprise, U-Haul, etc. was just over $100 a day plus mileage but sometimes if you call U-Haul headquarters directly, you can get a better deal.

 

[Rayson1971]

Maybe use the f450 with the diesel in the left corner of your pic.

 

[Tank]

Tank It in Havasu can build you a tank 928-505-2030

Place does good work. I’ve seen one of his custom fuel cells in AJ’s F450. Bad ass. I don’t think he’s crazy expensive either. Custom so gonna cost a bit but not outrageous. Have him do exactly what you want. No guess work. Done and done.

 

[hallett21]

How many gallons of gas are you burning to get to Havasu?

 

[Waterjunky]

Given the age of the truck many of the tank builders won't touch it. Transfer flow out of Chico is by far the best system but they only do newish stuff. Not worth their time even when they have the patterns and such. I talked with them extensively about square body fords. These guys are the only ones still making stuff for the classics. https://aerotanks.com/

Actually working with them currently to build an auxiliary tank for my Super C. They are the only ones I've found willing to take a project like that.

 

[575cat]

Maybe use the f450 with the diesel in the left corner of your pic.

Whats the worser of 2 evil,s ?? the chev doesnt come with tailgate warmers though

 

[RVRKID]

At 6MPG i would tow it with an RV to LOTO and at least save money on hotel rooms.

 

[Sportin' Wood]

Every Suburban in that Era had a big tank in back. Then they switched to duals with a BCM that transfers from the rear tank, so it seems like a single. With the Excursion's, a single plastic 38 gallon tank.
In Dan's case, the rear tank would be near 5ft in the air. If he gets hit by something big enough to rupture it, he's already had a really bad day

That is the first thing I thought of when I saw this post. If I recall, that was the hot set up back in the day. Just use it as a transfer tank.

 

[81Sprint]

Swap in an LBZ and 6 speed Allison. Reliable, efficient and still cool factor of the squarebody.

 

[coolchange]

Gravity flow bed tank, "Transflow" maybe? On my old dually I cheaped out, ran a tank in the bed, an electric fuel pump, and a twist timer from a toy hauler so it would shut off if I forgot...which was common.

I did this on an 1954 Lincoln Capri that I rally prepped. Only my timer was a giant hand painted sign on the dash that
said.”Shut off fuel!”

 

[coolchange]

More like 400 towing, i got 6mpg towing but now that i have the long tube headers and fixed the two fried spark plug wires hopefully it goes up

6.2