Best way to convert Saddles to 40 Gallon Suburban Tank?

[dbreid]

All,
I have a K30 with factory Saddle tanks. I actually like them, because they carry a ton of fuel, and I like the weight distribution. But they are kinda in the way of me putting in good rockers and or boatsiding a little, which is what I want to do.

I considered a fuel transfer style tank in the bed, and a few other options, but I am leaning towards a Suburban Tank (40 Gallon) under the bed.

I will likely buy one new from LMC, but I have questions..

Questions:

1.) How did you mount it? To the frame? Through the bed floor? What straps did you use? 40 gallons of fuel weighs a LOT, and I'd like to keep it under there....
2.) How did you hook up the filler? I'd like to use the factory fuel filler if possible (will make it easier when smog time comes around again to not have to explain....) Were you able to mount it forward enough?
3.) What sending unit did you use? Can I reuse the old unit, or do I need a new one of those too?

Thanks in advance, especially for pictures.

-Dan

 

[dremu]

While it sounds easy ... fitting a 40 gallon tank under there is a PITA. You'll have to remove at least one crossmember and/or the crap for the spare tire in the very back, if so equipped. Pretty sure it has to go in back of the rear axle and not in front. Maybe with a big body lift and no mufflers... or you could cut the bedfloor and drop it halfway through, with the seam in the middle of the tank at about bed level. The 40 gallon tanks are BIG... LMC catalog says 35 x 28 3/4 x 13 1/8.

Note that pickups with a rear tank have a 25 gallon one, not the giant Burb tank.

Did I mention I'm still contemplating the best way to do the same thing you want to do?

As for a filler pipe, I have this pic I got somewhere (here? Ebay? I forget)

LMC lists widely varying part numbers for the senders for the saddles and the Burb tanks, so I'm gonna say you'll need to get a sender specific to that tank as well. That you could prolly do junkyard as opposed to paying a ton @ LMC.

I lucked out and traded someone a Blazer tank for a Burb, so I have the 40 gallon ... just donno what to do with it. I am debating actually putting it in the bed, under the toolbox, and plumbing it as a transfer tank.

-- A

 

[dbreid]

I was kinda afraid of that.... I am not cutting the bed and dropping it halway in (not that I care about cutting, but I don't want it sticking through sheetmetal....). WHat about a flat type Fuel cell? Anybody ever run one of those (has to be DOT approved, of course)?

 

[dbreid]

Here's one from Summit:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=GMK%2D4175%2D750%2D823&N=700+4294842782+4294925044+115&autoview=sku

 

[Russell]

I have a 40 gallon burb tank in my K25.

Mounting it is quick and easy, but routing the filler neck is a MAJOR pain in the backside.

For mounting I used the factory rear crossmember from the Burb and replaced the one that was in my truck already with it. I had to move the crossmember right to the rear of the frame rails so the tank would not hit the 14 bolt at full compression, and to make sure that the front crossmember didn't move up too high as the rails raise for the wheel arch. That gave me the rear bolting point, and a curved crossmember that fit the tank. Up front I used the factory spare tire hanging crossmember flipped upside down with a 1" spacer for the tank to press up against, then installed a piece of angle iron as a crossmember for the straps to hook on to.

With the flipped spare tire crossmember, the tank sits perfectly level, and the angle iron / factory rear crossmember allows you to use the stock straps. The factory skid plate will bolt on to the rear, but you'd have to fabricate mounting points for the front to fit. I am personally not running a skid plate on my truck since it is lifted 6" and will not be taken off-road.

The filler neck I did is the same as the dually that dremu posted. I cut out a square in the box side and installed a filler neck opening I cut from a truck at the wrecking yard, then welded it in. On the back side I had to cut the inner box wall for the filler neck to fit through.

Unfortunately I was a moron when I did the install and put the fuel door at the same elevation as the front one, which is too low and makes it impossible to fill (fluids don't go uphill naturally!). I'll have to cut it out and re-do it so the filler door opening is just below the body line.

Inside the box side I took the round part from inside the suburban, and cut it out, but have not welded it in yet. It may take a bit of work to massage it in, but I'll have to cut my box up more to raise the filler neck high enough for it to reach the filler door.

And yes, while mounting that tank you have to trim the box crossmember that sits directly above the sending unit in the tank. I cut it so it was only an inch long, then boxed it in with some flat iron stock.

Installed the tank sits about 2" below the step bumper, and I imagine that there will be a big difference in ride when it is full vs empty. Here is a link to the website I used as a reference when I did my install: http://www.captkaoscustoms.com/blazertank.html