gas tank conversion from in cab to under bed - The 1947 - Present Chevrolet & GMC Truck Message Board Network

marc70chevy · 06-25-2009, 12:37 AM

i bought a tank from a late 70's model blazer and it was too tall. i have a 1970 chevy longbed and there is an extra support bar going across me bed that hangs down about 3 inches, which made the blazer tank not fit. The replacement rear gas tanks from LMC look to big, and are 21 gallon tanks which really make me think they are too big. where can i buy i gas tank that is not so tall?

Longhorn Man · 06-25-2009, 11:32 AM

Moving to the truck forum, was posted in the suburban area.

Sammy · 06-25-2009, 12:02 PM

The cross sill is to be removed. Check FAQ on the install. Otherwise no tank will fit. Unless it's 6 gal tank to fit between the sills.

marc70chevy · 06-25-2009, 01:12 PM

Do you know where i can get a 6 gallon tank, i just drive around town, 6 gallons is enough. I really don't want to cut out that support bar

glock35ipsc · 06-25-2009, 02:06 PM

The cross sill needs to be notched, that's just how this install works. Unless you have a wood bed, then it's easy to replace it with the shorter cross sill.

If you don't want to notch it, get a tank made by board member Fuelcellguy (http://www.aluminumfuelcell.com/), or look for a fuel cell from Summit or Jegs.

marc70chevy · 06-25-2009, 02:12 PM

when i notch it should i reweld the bottom back to it so it still has support or is that unnecessary

glock35ipsc · 06-25-2009, 02:15 PM

If you have a welder and want to do it, it sure wouldn't hurt anything. But of all the swaps I know of, no one has welded anything back in.

**michael bustamante** · 06-25-2009, 02:25 PM

im gettin ready to install a lmc tank also in my longbed metal floor. I knowyou gotta take out the crossmember thats in the way but you still have to notch the other?

marc70chevy · 06-25-2009, 03:33 PM

"im gettin ready to install a lmc tank also in my longbed metal floor. I knowyou gotta take out the crossmember thats in the way but you still have to notch the other?"

My blazer tank is almost the esact same dimensions as the one LMC sells. I have already taken out that crossmember, but that bar that is attached to the bed that gets bolted to the frame is in the way. So i will probably notch it if that is my only option..

**michael bustamante** · 06-25-2009, 04:34 PM

I see. well I guess Ill have a look see when I finally get aound to installing my tank. thanks!

hgs_notes · 06-25-2009, 05:08 PM

I'm using a 75 blazer tank in mine. I haven't set the bed back down yet, but took a lot of measurements. What I found is that the filler and line connections need to be turned to the passenger side and it looks like the bed cross sills will sit just in front of and just behind the fittings and tuck up in between them.

I could cut the sills then it would tuck up higher though. About an inch maybe.

marc70chevy · 06-25-2009, 05:25 PM

your tank looks smaller than mine. what is the height of it?

Arizona oldguy · 06-25-2009, 06:04 PM

I installed an LMC 21 gallon tank in my 72 short bed, I removed the cross member, I believe that it is only there for the spare tire it was not very heavy, find it hard to believe that it was doing much.

hgs_notes · 06-25-2009, 09:00 PM

Quote:

Originally Posted by marc70chevy

your tank looks smaller than mine. what is the height of it?

It's the 25 gallon and is about 11" high. The 31 gallon is about 13".

hemihead · 06-27-2009, 10:44 PM

Have people put the tank flange under frame or between the frame flanges? Hoe did people attache the straps.? More pics of install if anyone has.

thanks

marc70chevy · 06-28-2009, 08:12 PM

i have seen people weld the straps to the frame. but i'm going to bolt them to the frame through an existing hole

hgs_notes · 06-29-2009, 10:53 PM

I just ordered new replacement straps for my tank. They are about $30 new.

marc70chevy · 07-07-2009, 04:58 PM

ok, my next question might be a dumb one, but do i have to run hard fuel lines, or can i just run a rubber one all the way, because i am not a very good tubing bender

C20-67_N_MO · 07-07-2009, 05:16 PM

Quote:

Originally Posted by marc70chevy

ok, my next question might be a dumb one, but do i have to run hard fuel lines, or can i just run a rubber one all the way, because i am not a very good tubing bender

I want to know the answer to this as well, since I am doing this conversion to my truck in the near future.

Keep us updated!!

**bowtie72** · 07-07-2009, 06:10 PM

I wouldn't run it that far in rubber. I think you can buy prebent from LMC. There are alot of issues with running rubber that far. Just as long as you use a tubing bender it isnt really that hard.

marc70chevy · 07-07-2009, 10:12 PM

yea, but i heard the prebent lines get messed up for packaging but i don't see how a rubber line that long will be bad. i know a hard line will be better, but i just don't see what could go wrong...

JaysC2072 · 09-23-2010, 01:34 AM

Quote:

Originally Posted by bowtie72

I wouldn't run it that far in rubber. I think you can buy prebent from LMC. There are alot of issues with running rubber that far. Just as long as you use a tubing bender it isnt really that hard.

I took the sender to a local hose shop and had them braze a male fitting on and then had steel braided made to the front, cost 100.00 bucks.

hgs_notes · 07-07-2009, 10:14 PM

I used some aluminum 3/8" fuel line from summit. Costs less than $20 for 25 feet. You can bend it by hand, it looks good, and shouldn't rust. I was able to run it through most of the stock clips, and just bought a bag of insulated tubing clips from the electrical section of the hardware store for the rest.

C20-67_N_MO · 07-10-2009, 01:57 PM

Ditto!

06-25-2009, 12:37 AM	#1
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	gas tank conversion from in cab to under bed i bought a tank from a late 70's model blazer and it was too tall. i have a 1970 chevy longbed and there is an extra support bar going across me bed that hangs down about 3 inches, which made the blazer tank not fit. The replacement rear gas tanks from LMC look to big, and are 21 gallon tanks which really make me think they are too big. where can i buy i gas tank that is not so tall? Last edited by marc70chevy; 06-25-2009 at 12:37 AM.

06-25-2009, 11:32 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: gas tank conversion from in cab to under bed Moving to the truck forum, was posted in the suburban area.

06-25-2009, 12:02 PM	#3
Sammy Registered User Join Date: Apr 2000 Location: Bonne Terre, Mo Posts: 3,005	Re: gas tank conversion from in cab to under bed The cross sill is to be removed. Check FAQ on the install. Otherwise no tank will fit. Unless it's 6 gal tank to fit between the sills. __________________ '69 Chevy Long Fleet & '71 GMC Short Step & Project "ODD BALL" "You can wash a pig, soak it in most expensive perfume. In the end it is still just a pig." ODD BALL build thread http://67-72chevytrucks.com/vboard/s...d.php?t=478629"

06-25-2009, 01:12 PM	#4
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	Re: gas tank conversion from in cab to under bed Do you know where i can get a 6 gallon tank, i just drive around town, 6 gallons is enough. I really don't want to cut out that support bar

06-25-2009, 02:06 PM	#5
glock35ipsc Next project: 1970 K10 Join Date: Feb 2004 Location: Fort Collins, Colo 80524 Posts: 6,685	Re: gas tank conversion from in cab to under bed The cross sill needs to be notched, that's just how this install works. Unless you have a wood bed, then it's easy to replace it with the shorter cross sill. If you don't want to notch it, get a tank made by board member Fuelcellguy (http://www.aluminumfuelcell.com/), or look for a fuel cell from Summit or Jegs. Attached Images __________________ *Bob* 1970 Chevy K10 LWB "Goldie" 350/TH350 *next project!!* 1981 Chevy C10 LWB 355/TH350 - My son's truck LS SWAP FORUM! Tons of LS swap info here! PLEASE CLICK HERE TO SUPPORT THE GREATEST BOARD ON THE NET! CLICK HERE FOR THE FAQ INDEX by KRUE Last edited by glock35ipsc; 06-25-2009 at 02:08 PM.

06-25-2009, 02:12 PM	#6
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	Re: gas tank conversion from in cab to under bed when i notch it should i reweld the bottom back to it so it still has support or is that unnecessary

06-25-2009, 02:15 PM	#7
glock35ipsc Next project: 1970 K10 Join Date: Feb 2004 Location: Fort Collins, Colo 80524 Posts: 6,685	Re: gas tank conversion from in cab to under bed If you have a welder and want to do it, it sure wouldn't hurt anything. But of all the swaps I know of, no one has welded anything back in. __________________ *Bob* 1970 Chevy K10 LWB "Goldie" 350/TH350 *next project!!* 1981 Chevy C10 LWB 355/TH350 - My son's truck LS SWAP FORUM! Tons of LS swap info here! PLEASE CLICK HERE TO SUPPORT THE GREATEST BOARD ON THE NET! CLICK HERE FOR THE FAQ INDEX by KRUE

06-25-2009, 02:25 PM	#8
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,850	Re: gas tank conversion from in cab to under bed im gettin ready to install a lmc tank also in my longbed metal floor. I knowyou gotta take out the crossmember thats in the way but you still have to notch the other? __________________ 1967custom

06-25-2009, 03:33 PM	#9
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	Re: gas tank conversion from in cab to under bed "im gettin ready to install a lmc tank also in my longbed metal floor. I knowyou gotta take out the crossmember thats in the way but you still have to notch the other?" My blazer tank is almost the esact same dimensions as the one LMC sells. I have already taken out that crossmember, but that bar that is attached to the bed that gets bolted to the frame is in the way. So i will probably notch it if that is my only option..

06-25-2009, 04:34 PM	#10
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,850	Re: gas tank conversion from in cab to under bed I see. well I guess Ill have a look see when I finally get aound to installing my tank. thanks! __________________ 1967custom

06-25-2009, 05:08 PM	#11
hgs_notes GEARHEAD Join Date: Aug 2003 Location: MN Posts: 6,122	Re: gas tank conversion from in cab to under bed I'm using a 75 blazer tank in mine. I haven't set the bed back down yet, but took a lot of measurements. What I found is that the filler and line connections need to be turned to the passenger side and it looks like the bed cross sills will sit just in front of and just behind the fittings and tuck up in between them. I could cut the sills then it would tuck up higher though. About an inch maybe. __________________ If no one knows what you're doing, they can't tell you you're doing it wrong HG's Dream Car Build - Shelby Cobra Kit Build your own adjustable track bar 71 Long Fleet C/10 72 Jimmy 4x4 (Junkyard Jimmy) HG's Plow Truck '78 K35 Dually Bigass Farm Truck HG's thread of miscellaneous stuff Last edited by hgs_notes; 06-25-2009 at 05:09 PM.

06-25-2009, 05:25 PM	#12
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	Re: gas tank conversion from in cab to under bed your tank looks smaller than mine. what is the height of it?

06-25-2009, 06:04 PM	#13
Arizona oldguy Registered User Join Date: Jan 2009 Location: Queen Creek Arizona Posts: 56	Re: gas tank conversion from in cab to under bed I installed an LMC 21 gallon tank in my 72 short bed, I removed the cross member, I believe that it is only there for the spare tire it was not very heavy, find it hard to believe that it was doing much.

06-27-2009, 10:44 PM	#15
hemihead Registered User Join Date: Mar 2007 Location: Estevan, Sask, Canada Posts: 185	Re: gas tank conversion from in cab to under bed Have people put the tank flange under frame or between the frame flanges? Hoe did people attache the straps.? More pics of install if anyone has. thanks __________________ 1967 SWB C-10, BBC 454, T400, 3.73 posi, 20" Coys 1972 K5 Blazer, SBC 400, 4 spd, 3.73, 6" lift, 35" mud grapplers 2011 Sierra Denali HD, 6.6 L Duramax, RBP 96R rims, leveled and Nitto trail grapplers, 2009 Acura MDX

06-28-2009, 08:12 PM	#16
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	Re: gas tank conversion from in cab to under bed i have seen people weld the straps to the frame. but i'm going to bolt them to the frame through an existing hole __________________ http://www.cardomain.com/ride/3327115



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06-29-2009, 10:53 PM	#17
hgs_notes GEARHEAD Join Date: Aug 2003 Location: MN Posts: 6,122	Re: gas tank conversion from in cab to under bed I just ordered new replacement straps for my tank. They are about $30 new. __________________ If no one knows what you're doing, they can't tell you you're doing it wrong HG's Dream Car Build - Shelby Cobra Kit Build your own adjustable track bar 71 Long Fleet C/10 72 Jimmy 4x4 (Junkyard Jimmy) HG's Plow Truck '78 K35 Dually Bigass Farm Truck HG's thread of miscellaneous stuff

07-07-2009, 04:58 PM	#18
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	Re: gas tank conversion from in cab to under bed ok, my next question might be a dumb one, but do i have to run hard fuel lines, or can i just run a rubber one all the way, because i am not a very good tubing bender __________________ http://www.cardomain.com/ride/3327115

07-07-2009, 06:10 PM	#20
bowtie72 Registered User Join Date: Mar 2007 Location: Colorado Posts: 361	Re: gas tank conversion from in cab to under bed I wouldn't run it that far in rubber. I think you can buy prebent from LMC. There are alot of issues with running rubber that far. Just as long as you use a tubing bender it isnt really that hard. __________________ 1968 SWB "Little White Truck" 1972 LWB LS 4l80 "Plain Jane!!"

07-07-2009, 10:12 PM	#21
marc70chevy Registered User Join Date: Jun 2009 Location: League City, Texas Posts: 82	Re: gas tank conversion from in cab to under bed yea, but i heard the prebent lines get messed up for packaging but i don't see how a rubber line that long will be bad. i know a hard line will be better, but i just don't see what could go wrong... __________________ http://www.cardomain.com/ride/3327115

07-07-2009, 10:14 PM	#23
hgs_notes GEARHEAD Join Date: Aug 2003 Location: MN Posts: 6,122	Re: gas tank conversion from in cab to under bed I used some aluminum 3/8" fuel line from summit. Costs less than $20 for 25 feet. You can bend it by hand, it looks good, and shouldn't rust. I was able to run it through most of the stock clips, and just bought a bag of insulated tubing clips from the electrical section of the hardware store for the rest. __________________ If no one knows what you're doing, they can't tell you you're doing it wrong HG's Dream Car Build - Shelby Cobra Kit Build your own adjustable track bar 71 Long Fleet C/10 72 Jimmy 4x4 (Junkyard Jimmy) HG's Plow Truck '78 K35 Dually Bigass Farm Truck HG's thread of miscellaneous stuff

07-10-2009, 01:57 PM	#24
C20-67_N_MO Champagne Taste on Beer Budget Join Date: Dec 2008 Location: High Ridge, Missouri Posts: 2,190	Re: gas tank conversion from in cab to under bed Ditto! __________________ Coming Soon: Project 1970 Country Truck

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