Converting from dual saddle tanks to a single fuel tank

[bucket]

Lol, really? Just like asking someone for the answer without doing your own homework will turn up incorrect results, except you won’t know because you don’t have enough motivation to verify.
Same thing.
Plus, the new AI chats that pop up the instant answer are generally accurate, depends how specific or general of a question or how well you ask it. And then there’s the “old fashioned” internet…. Lol
Look up the part for sale at _____ company. Or, search a forum like this for the info rather than asking someone else to.
This isn’t like asking for help on fixing something you’re stumped on. This is like asking someone to order your McDonalds for you at the drive thru so young don’t have to read the menu, talk, or use the app.

Bad enough that kids (like mine, yours and everyone’s) struggle with self generated problem solving skills. Worse that full blown adults have also succumbed to this.

I also noticed that you didn’t give him the dimensions @bucket. Why not?

I didn't give the dimensions because I'm out of town. If I was home, I would have went out and got measurements of factory tanks (I've got all three) and got pictures of all three installed on trucks. Including a 25 gal installed on a K10.

I wouldn't have minded it at all, it wouldn't have taken much effort, it would have put all the info in one place and it would have been useful info for OP. It's really not a worn out question. It's not like he asked if he can clear 33's with no lift.

 

[Turbo4whl]

It's not like he asked if he can clear 33's with no lift.

^^^ ^^^

 

[Ricko1966]

He should read this

https://www.gmsquarebody.com/threads/write-up-gas-tank-relocation.663/

 

[goldpack]

just throwing some ideas. in an effort to put the tank before the rear axle:

mount the spare in the bed vertically.

get access to a 2000-2005 era gmc / chevy with a plastic tank, a whole one at your garage would be nice so you can hog it for parts by just walking, running rust bucket with snapped frame, or one run out of oil. (toss it for scrap when the project is running complete)

buy a new fuel filler line if it does not already have one. (others have showed a filler line in the bed of a squarebody, either by trapped door, nozzle up through the bed, or a knee sized piece of welded on steel so the filler door can be in the bed side. (so still neat and handy for campers/ caps)

a 2002 5.3 yukon xl or suburban may have a 32 gallon plastic tank on the drivers side with the fuel filler close to the tailgate. with a single exhaust down the passenger side. (shorter bodies have smaller tanks, seen some others listed as 29...it varies).

my 1986 has mammoth rumbling duel mufflers up before the rear axle. I presume they stuck them there for under the tailgate spare,...and wow what a weird use of space. but I think the smarter place would be in the back by the tailgate cross ways. not sure where the late 1980s / 1990s were.

 

[Grit dog]

not sure if there are threads putting the mid 80s square bodies saddle tanks like a 70s one, or into the 1990s and later.

just throwing some ideas. in an effort to put the tank before the rear axle:

mount the spare in the bed vertically.

get access to a 2000-2005 era gmc / chevy with a plastic tank, a whole one at your garage would be nice so you can hog it for parts by just walking, running rust bucket with snapped frame, or one run out of oil. (toss it for scrap when the project is running complete)

buy a new fuel filler line if it does not already have one. (others have showed a filler line in the bed of a squarebody, either by trapped door, nozzle up through the bed, or a knee sized piece of welded on steel so the filler door can be in the bed side. (so still neat and handy for campers/ caps)

a 2002 5.3 yukon xl or suburban may have a 32 gallon plastic tank on the drivers side with the fuel filler close to the tailgate. with a single exhaust down the passenger side. (shorter bodies have smaller tanks, seen some others listed as 29...it varies).

my 1986 has mammoth rumbling duel mufflers up before the rear axle. I presume they stuck them there for under the tailgate spare,...and wow what a weird use of space. but I think the smarter place would be in the back by the tailgate cross ways. not sure where the late 1980s / 1990s were.

Without going into details this entire post sounds like a solution looking for a problem.
There are so many easier, made to fit or minimal extra work needed, with brand new economical parts mad to fit in a squarebody, I’m not sure what the basis of a franken tank system would be.

 

[goldpack]

Without going into details this entire post sounds like a solution looking for a problem.
There are so many easier, made to fit or minimal extra work needed, with brand new economical parts mad to fit in a squarebody, I’m not sure what the basis of a franken tank system would be.

well I did not say my ideas were good. just idle thoughts while looking at for sale 25 year old rust bucket pickups, and seeing posts of swapping engines into square bodies, and wondering if the fuel bits could go too and if it would be easy and functional.
(if not,...so be it).

I was also recently reminded of some tanks over the frame rails:
one of my neighbors had a 1983 ? 454 dully with a weird service body on it. he had a 80 gallon custom built tank that went across behind the cab. (I think it was originally a tractor trailer road service truck, tall boxes on the sides and a step in body,)

even cooler, one of my friends from high school had a 1977 with a 305 ?, a fire wood getting off roader, all rusted to h3ll to look at, barely roadworthy, no actual plates, but only crossed the paved road,...or crept down the shoulder. no tanks mounted on it at all. ...use to run on 5 gallon army kind of jerry cans, with the pump dropped in the lid. I seen his father at a local Napa 2 weeks ago. His dad still has it hidden in rotten old barn, it has not run in 30 years,...but he thinks it could start right up.

 

[Grit dog]

^ my bad. I sometimes presume if you’re posting it you’re serious or looking for an opinion and not just hypothetically spitballing.
Fwiw Also all squares fuel tanks are basically the same. 80s to 70s isn’t a “swap.”

Although now I know why the plastic tank suggestion.

 

[Hunter79764]

Searching Google will often turn up a bunch of incorrect results though too. We are here to help, not just say to search on the internet. I'd like to think that many of us here often have better and more correct answers than what might be found elsewhere.

Now with all that said, there were 25, 31 and 40 gallon tanks. 25 and 31 were used in the K5, they share a footprint, but the 31 gal tank is a bit deeper. Burbs got the 31 or 40 gal. The 40 gal tank is longer and not at all a good fit for a shortbed pickup.

There are different ways to do the swap. Custom brackets can be made, simple or elaborate. Also brackets from a donor K5 frame can be used.

Slight correction for the record, burbs did get the 25 gallon as well, just probably not as often. My 87 was an odd duck, I'm sure, but it's a 3/4 ton 4x4 with the 25 gallon tank, at least I'm pretty sure that's what it is. I ran it scary low and put about 24 gallons in, but technically it wasn't sputtering and stalling yet, so...?

 

[bucket]

Slight correction for the record, burbs did get the 25 gallon as well, just probably not as often. My 87 was an odd duck, I'm sure, but it's a 3/4 ton 4x4 with the 25 gallon tank, at least I'm pretty sure that's what it is. I ran it scary low and put about 24 gallons in, but technically it wasn't sputtering and stalling yet, so...?

You would have to measure the depth of the tank. Every Burb and K5 I've had, running them down to E still left a few (or several) gallons in the tank.

 

[Bennyt]

I wouldn't bother with Burb tank unless you had a brand new one that you got free.

CPP makes/sells a bolt in tank.
Rick's makes/sells a bolt in tank.
POL/ Western Chassis, I think, makes a tank.

Have to drill 6-8 holes and they bolt in.

Possible Issues to deal with:
Wood bed floors reduce clearance.
56" spring hanger bolts may interfere.
Have to fabricate figure out how to fill. I went through bed floor but if you haul often, might interfere.
Spare tire provisions.

 

[Grit dog]

I wouldn't bother with Burb tank unless you had a brand new one that you got free.

CPP makes/sells a bolt in tank.
Rick's makes/sells a bolt in tank.
POL/ Western Chassis, I think, makes a tank.

Have to drill 6-8 holes and they bolt in.

$$$$ though. Those are more the high $ hot rod build category.

 

[Grit dog]

You would have to measure the depth of the tank. Every Burb and K5 I've had, running them down to E still left a few (or several) gallons in the tank.

I wonder the “actual” volume vs published for these trucks. I stupidly ran a new Chebbie truck out of gas a few years ago. Hour long Teams meeting on the screen doing 90mph across E WA to work in the morning, forgot to hit my fuel stop exit… hiked back to another exit about 2 miles and 50 miles past where I was gonna fill up!
It took about a half gallon more than the stated capacity to fill up til the pump clicked off. Including the 2 gal I packed back in a gas can!
Both squares, dual working tanks makes it a fun game to verify gauge vs tank, I’ve run low enough that got a couple sputters but not totally sucking air and put 19.x gal in the tanks. Is there still a couple gallons sloshing around? Or a couple quarts?

 

[Grit dog]

I didn't give the dimensions because I'm out of town. If I was home, I would have went out and got measurements of factory tanks (I've got all three) and got pictures of all three installed on trucks. Including a 25 gal installed on a K10.

I wouldn't have minded it at all, it wouldn't have taken much effort, it would have put all the info in one place and it would have been useful info for OP. It's really not a worn out question. It's not like he asked if he can clear 33's with no lift.

That’s very kind of you for sure.
Apologies if my frustration of enabling (anyone) to not use their own time and brain to their abilities is showing through.
Between my 2 great kids who are both legal adults and still think answers come instantly from the phone/computer or from DI (Dad Intelligence) and the numerous others at work who are or act the same, it gets annoying some days…lol.
I look at it as a lesson in becoming more self sufficient. Actually.

 

[Grit dog]

I wonder the “actual” volume vs published for these trucks. I stupidly ran a new Chebbie truck out of gas a few years ago. Hour long Teams meeting on the screen doing 90mph across E WA to work in the morning, forgot to hit my fuel stop exit… hiked back to another exit about 2 miles and 50 miles past where I was gonna fill up!
It took about a half gallon more than the stated capacity to fill up til the pump clicked off. Including the 2 gal I packed back in a gas can!
Both squares, dual working tanks makes it a fun game to verify gauge vs tank, I’ve run low enough that got a couple sputters but not totally sucking air and put 19.x gal in the tanks. Is there still a couple gallons sloshing around? Or a couple quarts?

It’d been quite some time since I ran something other than the mower out of gas (unintentionally anyways). It was at that moment I coasted safely into the median to a stop that I really appreciated the “old, outdated” dual tank pickups sitting at home all snug in their beds.
Our squares aren’t real daily’s. Most of the time anyways. But on that day in bfe WA, sucking that fuel tank dry like the last of a milkshake when your straw makes that annoying noise, that little button on the dash of these old trucks would have saved me a 2 mile run (which I need anyways) and a 2 mile hike back.

 

[bucket]

That’s very kind of you for sure.
Apologies if my frustration of enabling (anyone) to not use their own time and brain to their abilities is showing through.
Between my 2 great kids who are both legal adults and still think answers come instantly from the phone/computer or from DI (Dad Intelligence) and the numerous others at work who are or act the same, it gets annoying some days…lol.
I look at it as a lesson in becoming more self sufficient. Actually.

It's all good. Personally, I'd rather trust someone that posts with real life measurements and pictures than piecing together various measurements and pictures from several different sources. In my mind, it makes it all more useful and helpful when everything is seen all at once. If that makes any sense. It's the next best thing to experiencing everything yourself in real life.