25 gallon Fuel tank in a SWB?

[Undone]

Will the tank not fit so the fuel inlet point towards the side of the truck? Tank is not same dimensions on both sides (square) ?

[Slowguy]

Originally Posted by Undone

Will the tank not fit so the fuel inlet point towards the side of the truck? Tank is not same dimensions on both sides (square) ?

I think it is square, and I could turn it I suppose, but why? I just want to figure out how to fasten it to the frame properly. Straps, bolts, etc? I had planned on doing like Jessie and chop the fill port and weld straight up for a bed fill. Figured that would be easiest.

[Undone]

Just wanting to know for myself about tank size square or not, same dimensions?

[hooperca]

Here's how I did mine. Not that it's right - it's just what I did. I made some straps out or 1/8 by 1 1/2 (I think?) steel from Home Depot for the top of the tank. Also used that for the bottom straps - bent them to "basically" fit the curvature of the tank. I took the new tank to a local radiator shop and they turned the neck about 93 degrees for me so I can have a side fill. I have no idea what I'm going to do with that yet but, given a lot of info on this site, I'll figure it out. I also used some rubber from a garage door seal - also from Home Depot - to make some "isolators" between the tank and the straps.

Hopefully, the pictures come out ok - never have posted pictures before.

What I'm really worried about more than anything is the integrity of the rear frame rails with the last "stiffener" removed. I think, under normal circumstances, it wouldn't be a huge deal once the bumper, etc. is mounted. However, I'd really like the capability to pull a small camper - maybe up to 22 foot or so. I worry about the ability to mount a hitch and, again, how strong and stable the frame rails will be to tow with. Any suggestions would be GREATLY appreciated!!

OK, so I guess I'm not smart enough to post pictures - I keep getting an error. If anyone can help me out, I'll try to get them posted. Sorry!!

[hooperca]

Oh, also, the tank is not square, I didn't measure it tonight but it's about an inch out of square. If you turn the tank 90 degrees it will stick out the back about another inch or so.

[hooperca]

One more thing. If you turn the tank 90 then the straps won't line up with the ribs in the tank and I would think the tank could possibly move on you. Lining the straps up with the ribs, it's not going to go anywhere.

[hooperca]

Here's some pics - maybe!

[Slowguy]

Thanks for the description and the pics! That helps tremendously. I’ll do exactly as you did, it looks great.

[Slowguy]

Btw, by looking at the bars running across the top, it appears your tank is basically flush with the top of the frame? If I bring those side seems of the tank against the bottom of the frame my tanks protrudes above the frame rails. Did you bring the side seems of the tank up high enough that they contact the underside of the frame rail?

[Slowguy]

Originally Posted by hooperca

One more thing. If you turn the tank 90 then the straps won't line up with the ribs in the tank and I would think the tank could possibly move on you. Lining the straps up with the ribs, it's not going to go anywhere.

Oh, one last thing; those upper straps won’t get in the way of bed bolts will they?

[hooperca]

The straps on top are flush with frame rails. The sender/pump “hump” is right under one of the bed braces so that brace will need to be trimmed to clear it. I kept the tank as low as feasible to minimize impact to that bed brace. The seam does sit below the bottom of the frame. However, I think the tank will still be completely covered by the bed and bumper.

Unless my measurements were wrong 🤨 the straps should miss the bed bolts. The bed bolts go through that very end hole on the frame, the one that’s slotted, and the one 12” forward of it. There’s a pretty substantial “stand” around that back hole which is why I notched those back straps .

I haven’t tried fitted the bed yet so I’m hoping it’s not going to be an issue other than the one brace I mentioned.

Keeping my fingers crossed 🤞

[Slowguy]

Thanks again for the response. This really helps and I like how you have it set up. I’ll do mine exactly the same. It’s not that I can’t figure it out through trial and error but it’s such a time time saver when someone else shares their findings. Going to buy the mounting hardware today!

[hooperca]

@ Slowguy - well if you're going to do what I did...I hope I'm right!

But to ease your mind, I did spend quite a bit of time measuring, sketching, etc. to make sure it works out. I'm glad I could help you out. I've gotten so much information and help on this site it's not even funny. Glad I could pass it forward as they say!

[Slowguy]

I think I’ve got a good start. Got the lower brackets bent now I either need to rig something up on the shop press to bend the 90’s or swing into the machine shop. I think I got the front upper bracket a little too far forward. May need to drill another set of holes to scoot it back a touch. I don’t think I want the tank to actually touch that front crossmember. I also have to figure out the fill neck because the back upper brace touches it and won’t allow me to scoot the tank back any further. I think I’ll chop the bend out, save the short straight piece and solder it back onto the tank. Then if I need just a little more wiggle room I can notch the back upper brace just a touch where it contacts the fill neck. Thanks again for your pics. It really put it into perspective and is making this much easier

[hooperca]

Glad things are working out for you. I did notice one other potential problem though. The top of the raised ribs on the tank can't be any higher than the top of the frame. If you notice on my pictures, those raised ribs are a little higher than the top of the frame. The lower portions - where the straps are, are basically level. However, the braces on the bottom of the bed are straight and will sit right on top of the frame rails. So, those raised areas will be too high. Not a big issue I don't think. Maybe tack some additional stips to the top straps to lower the tank a little and just don't draw up the bottom straps?? Haven't really thought through it yet but, again, don't think it's a big deal.

I've moved on to my exhaust for now. But, if you come up with something on lowering the tank to completely clear the bed braces, please fill me in! Again, the bed braces will be located at those very back slotted holes on the end of the rails, and the set of holes that are 12" forward of those slotted holes. Everything else should be ok as the next bed brace will be attached where the frame raises for the rear suspension, etc.

Together, we'll figure it out!!

[Slowguy]

So I'm pretty sure what you are saying. I didn't even thing about the side to side supports of the underside of the bed. I wonder if that flared part of the tank that protrudes upward (that the fill neck attaches to) will get in the way of any part of the bed? I was going to chop it and solder in straight up this afternoon but I don't think I'll have time now. Maybe tomorrow.

Anyway, does your tank have as much gap as mine between the underside of the frame rail and the flat seam that runs all the way around? It really doesn't matter I think as long as the tank is strapped securely from the lower straps pressing the tank upward into the upper bars we made. It just doesn't seem from your pics that the seam hangs down as far as mine? Maybe it's perspective I hope. Also, hopefully this thread helps others wondering the same things. Here are few more pics...and remember I just have it kinda hanging there until everything dry-fits perfectly.

[hooperca]

I don't think anything around the fill neck will be a problem. It's more the very back side of the tank where the very last bed brace will be - to the rear of the fill neck - and the big hump where the fuel pump/sender unit is. That is right in the way of the second, from the rear, bed brace. Kind of like where your straight edge is in your last few pictures. That second brace is going to have to be trimmed quite a bit to get over that hump. However, if the tanks are kept to where the top of those "corrugations" sit level to, or slightly below, the frame rails, then I don't think the trimming will be significant. Those braces are about 3 to 3 1/2 inches if I recall so that should be ok.

Yes, that seam where the two tank halves are joined hangs down quite a bit below the bottom of the frame rail - about like yours. By the way, those two areas on each side of the tank flange that looks like the flange is bent are where the two bottom braces should go. I will say, with mine bolted in, it's not going to go anywhere. The two bottom braces hold it real solidly from moving side to side and the top and bottom braces located in those "low" areas locks it in front to back.

Obviously, the tank will work. Jessemthompson, member on this site, has already done it. We just need to get the details figured out. We'll get there!

[Slowguy]

Here's an update. Got the top of the ribs below the top of the frame rail. Straps may bow up slightly but we'll see how it fits with the bed in place. worst case, I'll need to add some washers to the bolts that hold the upper straps in place, thereby spacing the straps down a little further. Oh, and btw, really easy to modify the fill neck. I see that most of the bed fill kits use a 1.5" ID hose to attach to the fill neck. They use silver solder to attach the fill pipe to the tank. I heated it up, popped it out, cut out the straight section, took a measurement and see that the pipe itself it 1.5" OD so I just flipped it over and soldered it back in. My only slight concern right, since I'm on bags, is that it doesn't hang too low. I would never drive aired out, so I don't think it will be an issue.

[hooperca]

Yeah, that's looking good. As far as how low it hangs, it still won't hang as low as the other blazer tanks that are so common. I guess there's no perfect solution - all a matter of compromises. I was like the original poster though, with a 6.0 I wanted a little more fuel on board. I intend to drive mine a lot - if I ever get it done!

[Slowguy]

Mine could be even worse; 6.0 with a turbo! So that’s how I found my way to the thread as well. It’s seemed like the perfect option. I knew I didn’t like the fuel sloshing around behind my back and the constant smell of gas, and I knew I’d like to get as much fuel as possible per fill up. No idea what the 6.0 will get for mpg on the highway (never cared enough to research it) but assuming at least 12 but probably more like 15-16 depending how I drive. 375 before fueling would be nice on a road trip.

[prodjay10]

How did this turn out? What did you use for a filler?

[Slowguy]

I’ll see if I can get a pic soon. I just purchased one off eBay, actually not bad quality. Fastened it with a 1.5” rubber plumbing coupling and a couple hose clamps. I don’t know yet, because the beds not on, but it looks a little tall. I may have to make a modification once is see how it all sits with the bed in place.

[Slowguy]

Here’s my cap so far.

[hooperca]

Unfortunately, I’ve been completely sidetracked and might not get back on my truck for quite a while. In the process of relocating from Louisiana to Georgia due to a job change. @ Slowguy - glad to see you’re still moving forward on your project! It’s looking good.

[Slowguy]

raising the post from the dead..

I'm doing the wiring now. On my ls harness the guy left a single lead for "fuel pump". There are three wires total going to the inside of the tank. One is an obvious ground strap but I'm unsure of the other two. Do you know which is which? one is purple and one is grey. One must be power for the pump and the other for the float to the gas gauge?