The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevy/GMC Suburbans & Panels Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-22-2018, 01:37 PM   #1
Burbnasty
Registered User
 
Join Date: Mar 2015
Location: Michigan
Posts: 47
Square body tank swap

I've searched lots of old threads about swapping a square body tank into the 67-72 suburbans and I found info on the pickup trucks and some limited info on our trucks.

Does anyone have any experience or info on the swap.

I think I want to use a 31 gallon tank because it looks like it wont hang down as far.

My tank smells of old gas and the only replacement I've found is a 21 gallon tank, I don't think anyone makes a larger one that i have seen.

It looks like the filler neck is in the wrong place on the square body and I will need to remove a cross member.
Burbnasty is offline   Reply With Quote
Old 01-23-2018, 08:24 PM   #2
lowrollin70gmc
Too many projects
 
lowrollin70gmc's Avatar
 
Join Date: Mar 2004
Location: Fargo, ND land of the flat hills
Posts: 1,147
Re: Square body tank swap

I have a 31 gallon square body tank in my 68. I cut off the tank filler and moved it to the other side of the tank (easy welding, as it was a new tank). I previously had a 55 gallon boat tank in it, so there weren’t any stock crossmembers remaining so I added a few square tube crossmembers to hang the 31 gallon tank straps off of.
__________________
Andrew
84 GMC C1500 SWB 6.2 Diesel/700R4/3.42 "Grandpa's odd duck"
70 GMC C1500 LWB My first truck: shaved, bagged, and more: the lowrollin70gmc
68 K20 Suburban 12V Cummins/NV5600/NP205/D60/11.5AAM 3.73s "Dakota Cadillac"
63 Chevy II Nova Coupe 250 I6/T56/4.56s "Economy car"
53 Willys Wagon 350/NV4500/BW4401/HP D44/9inch “Winter Wagon”
30 Model A 16 Focus ST
lowrollin70gmc is offline   Reply With Quote
Old 01-31-2018, 09:53 AM   #3
GWWhite
Registered User
 
Join Date: May 2013
Location: Long Beach, MS
Posts: 18
Re: Square body tank swap

On my 68 I purchased a tank and modified it to fit between the rails and under the supports. Cost a little but worth it.
Attached Images
  
GWWhite is offline   Reply With Quote
Old 01-31-2018, 02:12 PM   #4
Bigdav160
Registered User
 
Bigdav160's Avatar
 
Join Date: Apr 2011
Location: Klein Texas
Posts: 3,852
Re: Square body tank swap

AFAIK, the difference between the 31 gallon and the 40 gallon is the depth. I have a 40 gallon my Suburban and the width and length are perfect. And since I have 4WD the depth is no problem. It looks like it came that way from the factory.

To do so, you need to remove the rear crossmember and move it toward the rear. I purchased another (same) crossmember off the parts board and installed it ahead of the tank. This holds the tank at the top and allows for use of factory R-body tank straps.

Not mine but you get the idea:



Like lowrollin said, this puts the filler neck in the wrong position. If you can find flexible enough filler hose you might be able to heat the filler tube on the tank and swivel it around to make it work. I relocated mine to the corner also.

And since I went fuel injection I bought a fuel injection tank. I don't know if a carb or diesel tank are different, but the filler neck is about a 1/4" larger diameter. I had to glue a filler piece in the filler hose to mate to my filler tube.

Another view of mine:

__________________
My Classics:
'72 K20 Suburban + '65 Dodge Town Wagon
'72 Corvette Roadster +'67 Corvette Roadster
'73 Z-28 Camaro
'63 Ford SWB Uni Pickup
'50 Ford Coupe

Last edited by Bigdav160; 01-31-2018 at 02:24 PM. Reason: edit to add pic of my truck
Bigdav160 is offline   Reply With Quote
Old 01-31-2018, 07:00 PM   #5
Bigdav160
Registered User
 
Bigdav160's Avatar
 
Join Date: Apr 2011
Location: Klein Texas
Posts: 3,852
Re: Square body tank swap

Looks like Richard has the crossmembers for sale in the Sub parts area.
__________________
My Classics:
'72 K20 Suburban + '65 Dodge Town Wagon
'72 Corvette Roadster +'67 Corvette Roadster
'73 Z-28 Camaro
'63 Ford SWB Uni Pickup
'50 Ford Coupe
Bigdav160 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:21 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com