31-40gal gas tank upgrade

[TubeTruck]

I currently have a 31gal tank in my Suburban. I need a new tank, something is leaking from the top. I was thinking of installing the 40gal tank but when I check the measurements I'm not sure how it fits. My tank is sandwiched between to crossmembers. I can't go forward without hitting the rear axle, maybe backwards but I don't think there will be room to reinstall the crossmember. Has anyone done a tank swap/upgrade in a Suburban? All the research I find is using the 40gal tank in a pickup or a 31 in a Blazer.

My other thought was getting the '87 version since I'll be installing an L29 eventually with the correct pump for efi. Has anyone used this pump through a regulator for a carb? Just trying to avoid having to keep dropping the tank. I'd like to "one and done" if possible.

 

[bucket]

All my Burbs have had the 40 gallon tank. They are pretty close to the rear bumper/hitch area.

 

[Arkansas_V8]

All my Burbs have had the 40 gallon tank. They are pretty close to the rear bumper/hitch area.

Same here.

 

[Arkansas_V8]

The 40 is a big boy.

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[78C10BigTen]

X3 but my burb is a gmt400

 

[RecklessWOT]

What part is actually different between the 32 and 40 gallon tank? My burb originally rolled off the line with a 40 gallon tank, but has a 32 gallon tank under it now. I'd love to get a 40 gallon tank for it again but not sure how it will fit, there's a skid plate under the tank and I'm not sure if I'd need a different one. Basically what I'm asking, dimensionally what is the difference between the two. Or are they a different shape?

 

[Arkansas_V8]

What part is actually different between the 32 and 40 gallon tank? My burb originally rolled off the line with a 40 gallon tank, but has a 32 gallon tank under it now. I'd love to get a 40 gallon tank for it again but not sure how it will fit, there's a skid plate under the tank and I'm not sure if I'd need a different one. Basically what I'm asking, dimensionally what is the difference between the two. Or are they a different shape?

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[RecklessWOT]

So basically it's longer back to front, and fractions of an inch taller and wider? Oh I think I have the room for that lol.

Is that LMC by any chance? I have the 73-91 SUV catalog less than two feet away from me as I type this, should've just looked myself. Hah, didn't even think of it

 

[Arkansas_V8]

So basically it's longer back to front, and fractions of an inch taller and wider? Oh I think I have the room for that lol.

Is that LMC by any chance? I have the 73-91 SUV catalog less than two feet away from me as I type this, should've just looked myself. Hah, didn't even think of it

Yes LMC. Looked for a skid plate. Not in my book if they do sell them.

I was in mine when I saw your question. Here to save you that two feet. Lol

 

[RecklessWOT]

So it looks about the same, mine just doesn't go as far forward as the 40gal, yours looks like it extends over the axle almost

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[Arkansas_V8]

So it looks about the same, mine just doesn't go as far forward as the 40gal, yours looks like it extends over the axle almost

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Looks like your skid may work.

 

[TubeTruck]

Here is my 31 gal. It's sandwiched between the crossmembers that hold the straps. Can anyone take a pic of the 40gal crossmembers? I have the room to keep the front in the same spot and move the rear back but it's right where the frame drops down and I'm not sure if it'll fit further back. If it's the same crossmember I'll just grind the rivets and move it.

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[bucket]

Wow! There's s a lot of room behind the little tank. I'm not sure I've ever seen or noticed the little tank in a Burb before.

 

[Arkansas_V8]

Here is my 31 gal. It's sandwiched between the crossmembers that hold the straps. Can anyone take a pic of the 40gal crossmembers? I have the room to keep the front in the same spot and move the rear back but it's right where the frame drops down and I'm not sure if it'll fit further back. If it's the same crossmember I'll just grind the rivets and move it.

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Cant get a decent pic of the rear cross. But it is further back. Looks to be about the same as your front, but crammed alot deeper back.

My skid goes farther back, with my hitch blocking a decent view.

 

[Dooley]

X3 but my burb is a gmt400

All my square body Suburbans had the 40 gallon tank.
My 1972 3 dr Suburban with 402 BB had a 40 gallon tank also.
My 1994 Suburban with 6.5 Turbo diesel has a 42 gallon tank.