Having run my fair share with the local Fire Dept and Rescue Squad, we have had a couple instances over the years where gasoline in the cab turned out drastic. When I had someone ask recently if I'd relocate the tank on her 55 Chevy P/U, I was happy to oblige. She drives this rather frequently, and has been wanting to get the tank, fumes, and all such things out of the cab and out back under the bed of the truck. She had removed the bed the day before to make things go a bit easier and just trailered the truck over for the tank install. She had researched and was told a 70 Cougar tank fit nicely, and the 22 gallon size didn't hurt either. We needed some crossmembers to support the tank, so a section of 2 x 2 x 1/8 square steel tubing was procured and sliced down the middle to form two C-channels. They were cut to size, the tank centered, and holes match drilled. The tank was positioned in place, and we immediately noticed a clearance issue with the frame hitting the tank, so the "legs" of the rear frame rails were trimmed by about 3/4". A cuttoff wheel in a 4-1/2 grinder made short work of it, and a 1-1/2" drum sander gave some nice stress relief for the inside corners. The tank was positioned about as close to the shock crossmember as possible and still leave clearance in case we decided to run a fuel line between the two. This located the tank crossmember 28" from the rear of the frame rail, and it was located 1/2" down from frame to allow clearance for the bed crossmembers. The 7/8" hole is for tail light wiring. To make installation/removal a bit easier, some 5/16 bolts were welded to the crossmembers. The rear crossmember needed to be removable, so 3/8 nuts were welded into the end of the crossmember. A 3/8 wide relief cut was made so the bumper bracket could still slide in alongside the frame. Test fit: Looking along the side of the tank, it was obvious the bumper brackets at the front would leave no room for bolts/nuts on the inside, so an alternative arrangement was used: The next obstacle you see above is that once the rear crossmember is snugged down, the bumper bracket gets tight against the tank flange. Now I'm not one for cutting/trimming tanks, so a bit of bending was used instead: ......and that takes care of that issue. A gas cap is going in the bed of the truck, so an exhaust tubing adapter was mated with the top of a 55 wagon fill tube. And finally, to add some protection and prevent any Pinto reincarnations, the original crossmember was relocated to the back end. The frame rail width was 34, so this modification should work well with other trucks with the same width.
Nice job and good tech article. I don't think trimming the tank flange outside of the pinchweld would have caused any problems....since the weld is the seal. The best part is you can buy one of these brand new with sending unit for a little over $100.
Great Tech tip !! Thanks very much for posting this, since one of the next jobs I have on my '46 Chevy will be a similar installation and I'm sure it'll be a LOT of help.
Thanks for the post, I have been thinking about doing this to my 56. Is the sender that you are using for a Ford? If so, is that going to work with the Chevy gauge? I thought Ford and Chevy senders were different.
Slick. I'm looking forward to doing the same to my '62. I'm tired of smelling gasoline all day. Thanks for the tech.
Duffman, we got it from Kentucky Mustang (888-861-0176) they have a 65-68 tank and sender for 99 (I think that's a 16 gal), and the 69-70 mustang/Cougar tank (20 0r 22 gallon) was 109 with the sender. We used the 22. FordCragar, we still don't have the sending unit hooked up, but the guage is a Dakota Digital (from previous owner) so it should hopefully be more flexible with the input signal.
The senders read opposite of each other, the chevy gauge will read empty when full etc. When I did mine I bought a universal sender with the proper resistance for the chevy gauge and put it in the top of the Mustang tank, and used the mustang sender for the fuel outlet only (I think I cut the float arm off too). If you are using aftermarket gauges, just buy a fuel gauge for a Ford.
Thanks MP&C I will call them. My GMC is is build stage and I want to free up that space behind the seat where the stock tank sits.
Have you determined how you will be routing the exhaust? I found on my truck that to use a rear exit design I would need about 3.5 inches between the tank and the leaf springs to route the tail pipes. Since you are using coil overs this should not be a problem but you might want to ensure there is enough room between the axle and the front side of the tank for the over axle transition. If you are running side exit exhausts then disregard. Anyone using the leaf spring suspension though should keep the pipe routing issue in mind when picking a rear mounted tank. I was using a 67-68 camaro tank inmy 54 and found it was too wide. The 16 gallon universal tank from Tanks, Inc works well. Nice work!
What are the dimensions of that Cougar gas tank? I've also heard a '95 and below 30 or 40 gallon Chevy full-sized van tank will fot between the rails sideways. ~Jason
Here's what I noticed while scoping out my frame this weekend. The rear cross member that you moved is a mounting point for the leaf spring perch, not an issue on your 4- link, to be determined on my truck.
Here is a link to another thread on this topic: http://www.jalopyjournal.com/forum/showthread.php?t=324929
eBay or any Mustang vendor, just look for a Mustang tank, last one I bought was $129 complete. same as a Mustang. Early full size Blazer tanks also work great. 72ish.
I'm inspired to do mine - what material did you use between the tank and straps and the custom made upper supports?
2 ways to look at it though, the safest place to put the tank is in the cab because it is less likely to get damaged there, but if it does get damaged you are screwed
Not sure I follow the question, so clarify if I'm off base here, the Cougar (and Mustang for that matter) tanks bolt into a hole opening in the trunk floor of those cars using bolts through the flanges, no strap hangers that you normally see on other cars. The front and rear mounts that we did make were from a 2 x 2 x 1/8 wall square tubing cut in half on a band saw.
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