40gal Suburban fuel tank install.

[mckustomfab]

So i will start by saying that this may not be right, or even the best way, but this is how i mounted my 40gal suburban tank. And also this is my first attempt at a wright up so I apologize if its a bit scattered.

Starting with my 1991 R/V Crewcab conversion LWB, I removed the passenger side rear shock mount because it will be in the way of the tank. I then moved the rear crossmember as far back as possible and added a piece of steel to give the tank a little more to rest on. You can see from the pic how far back I moved the crossmember.



Then i held the tank up with a floor jack and go it level to see what i would have to do for the support that the front of the tank would rest on. Worked out that 2" square tubing sat the tank almost perfectly level, so i drilled and welded some sleeves in the 2" square and bolted it in.


To secure the straps i used a piece of angle iron running across the frame rail , I mounted mine close to the tank to make installing the tank less of a hassle.

I hooked up the straps and tightened it down. For clearance here is a pic of tank to rear diff cover clearance.


I will have to take a small section out of one of the ribs running under the bed floor. This is because the top of the tank humps up and the fill breather tub might make contact.


My plan for the fuel door is all based on speculation right now because i have not started on it and I am 8000mi away. But i plan to move the fuel door to behind the rear wheel well like it would be on a suburban. I don't foresee any problems with this but I will have to check when i set the bed back on. I also completely bypassed the switching valve switch and wired the pump into what would have been the passenger side tank. Everything seems to work good but i have to finish my outboard shock mounts before i can cruze around with it. For now it sits like this until the middle of October.


I'm excited to try it out but less so at the thought of spending about $130 bucks to fill it up!

[kevinr1970]

Cool, thanks for writing this up!
I was planning on doing something similar to my '91 2wd, but was thinking using a Blazer tank might be a better alternative fit wise; but I am also planning a making it a shortbed too.
I have a '91 Suburban to use for parts though, so it might just be easier to use whatever is under the Suburban!

[mckustomfab]

For a short bed a 25gal blazer tank should fit and maybe even a 31gal suburban tank. If you have a parts suburban i would use everything you can, rear crossmember etc. I had cut up a 2wd crew cab so i had a some of those parts laying around so Just used them! Good luck and let me know how it goes!

[K20chevy]

Originally Posted by mckustomfab

So i will start by saying that this may not be right, or even the best way, but this is how i mounted my 40gal suburban tank. And also this is my first attempt at a wright up so I apologize if its a bit scattered.

Starting with my 1991 R/V Crewcab conversion LWB, I removed the passenger side rear shock mount because it will be in the way of the tank. I then moved the rear crossmember as far back as possible and added a piece of steel to give the tank a little more to rest on. You can see from the pic how far back I moved the crossmember.



Then i held the tank up with a floor jack and go it level to see what i would have to do for the support that the front of the tank would rest on. Worked out that 2" square tubing sat the tank almost perfectly level, so i drilled and welded some sleeves in the 2" square and bolted it in.


To secure the straps i used a piece of angle iron running across the frame rail , I mounted mine close to the tank to make installing the tank less of a hassle.

I hooked up the straps and tightened it down. For clearance here is a pic of tank to rear diff cover clearance.


I will have to take a small section out of one of the ribs running under the bed floor. This is because the top of the tank humps up and the fill breather tub might make contact.


My plan for the fuel door is all based on speculation right now because i have not started on it and I am 8000mi away. But i plan to move the fuel door to behind the rear wheel well like it would be on a suburban. I don't foresee any problems with this but I will have to check when i set the bed back on. I also completely bypassed the switching valve switch and wired the pump into what would have been the passenger side tank. Everything seems to work good but i have to finish my outboard shock mounts before i can cruze around with it. For now it sits like this until the middle of October.


I'm excited to try it out but less so at the thought of spending about $130 bucks to fill it up!

I did a similar thing on mine by relocating the factory crossmembers foward and back. The rear crossmember looks just like yours is set up. I haven´t gottenaround to put my hitch in yet. Since one of your pics shows the hitch mocked up, do youhave a few more pictures on how the hitch clears?

I have a custom 45 gal tank in the back but I´m affraid that the hitch will not clear it when the first mounting hole needs to go in front of the two bolts holding the bottom of the crossmember in place.

Were you able to reuse factory holes in the frame for the hitch or did you have to drill all of them yourself? Does your hitch use 4 bolts per side???

Thanks for any info you can give me!

[mckustomfab]

I did a similar thing on mine by relocating the factory crossmembers foward and back. The rear crossmember looks just like yours is set up. I haven´t gottenaround to put my hitch in yet. Since one of your pics shows the hitch mocked up, do youhave a few more pictures on how the hitch clears?

I have a custom 45 gal tank in the back but I´m affraid that the hitch will not clear it when the first mounting hole needs to go in front of the two bolts holding the bottom of the crossmember in place.

Were you able to reuse factory holes in the frame for the hitch or did you have to drill all of them yourself? Does your hitch use 4 bolts per side???

Thanks for any info you can give me!

I had to clearance for the two crossmember bolts and i also had to drill new holes. The hitch i used is a class 4 and i got it used for cheap and i think it was off a 3/4ton truck so that may be part of the reason, but im not 100% sure.

I will grab some pics when i get home around xmas but the flange around the tank is close to the body of the hitch but it clears.

[K20chevy]

Originally Posted by mckustomfab

I had to clearance for the two crossmember bolts and i also had to drill new holes. The hitch i used is a class 4 and i got it used for cheap and i think it was off a 3/4ton truck so that may be part of the reason, but im not 100% sure.

I will grab some pics when i get home around xmas but the flange around the tank is close to the body of the hitch but it clears.

Thank you, any pics would be great. Mine is a class V hitch. I thought I might have to clearance for the bolts of the crossmember.

Thanks for the info! Looking forward to the pics!

[mckustomfab]

Sorry for the delay been busy around here.

Here is a pic of the gap between the tank and receiver. It's close buy it clears. I had to clearance the corners of the receiver to clear the tank crossmember bolts.


Here is my amateur attempt at body work. I moved the fuel door to work with my suburban tank, now I have to modify a fill neck to work with it.

[slotard]

What're the dimension differences between the 25, 31, and 40 gallon tanks? Does it hang down much below the frame? My C20 only has a single tank on it, below the passenger side, and I'd like to swap it out for something a little bigger, farther back would be nice too.

[mckustomfab]

Here is the info I used. For a long bed 2wd I would not go with the 40gal tank just because you may have clearance problems between the tank and the diff. a 31should be fine though.

[chevy-fun]

Looks good. Got a ? If i want to use the 25gal tank for rear an have a ls swap. Which tank should i get. An 87+ burban. Those had the baffels an pump for 60psi correct?

[y5mgisi]

Chevy-fun, 87+ did have baffles. But you have to get an ep381 or equivalent fuel pump. The stock ones in the 87-95 TBI do not supply enough pressure.

[mckustomfab]

Originally Posted by y5mgisi

Chevy-fun, 87+ did have baffles. But you have to get an ep381 or equivalent fuel pump. The stock ones in the 87-95 TBI do not supply enough pressure.

X2, I would get a tank from a 1991, they should be the same but that is my preference.

[chevy-fun]

Thanx for info

[K20chevy]

Originally Posted by mckustomfab

Sorry for the delay been busy around here.

Here is a pic of the gap between the tank and receiver. It's close buy it clears. I had to clearance the corners of the receiver to clear the tank crossmember bolts.


Here is my amateur attempt at body work. I moved the fuel door to work with my suburban tank, now I have to modify a fill neck to work with it.

Than ks!!

Do you have a detail pic of how you mounted the hitch with the rear crossmember bolts "in the way"? I´d like to see that. Maybe a shot from the bottom up where the hitch meets the frame!?

Thanks!

[mckustomfab]

Right now I am about 8000 miles away from the truck but when i get back i will get you a pic from below. Until then, this should give you a idea of what i did. Its not the exact same hitch butshould work as a example.

[K20chevy]

Originally Posted by mckustomfab

Right now I am about 8000 miles away from the truck but when i get back i will get you a pic from below. Until then, this should give you a idea of what i did. Its not the exact same hitch butshould work as a example.

Thank, that would be great!!

[mckustomfab]

This is the best picture I could get, I notched it just enough to clear the bolts.

[K20chevy]

Originally Posted by mckustomfab

This is the best picture I could get, I notched it just enough to clear the bolts.

perfect, thanks so much. That was exactly what I was looking for! I appreciate it!

[mckustomfab]

Originally Posted by K20chevy

perfect, thanks so much. That was exactly what I was looking for! I appreciate it!

No problem!