Gas tank and exhaust routing - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DarkFlounder · 01-23-2015, 08:12 PM

Sometime this year, I'm gonna replace the bed (eventually, the rust will stop holding it together), and while I've got the bed off, I'll probably put in a new under-bed gas tank.

I really like the 41gal Suburban tank between the frame rails I saw another post about. Without having climbed under and measured the space, would a tank this size be better placed forward or behind the axle?

And since I'm eventually going to have the exhaust redone (about as many holes and rust as the bed), I'm thinking about having the exhaust routed outside the frame rails (so they'll not be directly under the tank) and dumping out in front of the wheels.

Any thoughts? Should I stop thinking about the truck and get back to work (it's Friday after 4pm, leave me alone).

Mike C · 01-23-2015, 08:24 PM

Get back to work! Just kidding, it is Friday.

IMO, the Suburban tank is just too big. And there is no way to put it in front of the axle. If you want to ditch the in-cab tank, the best solutions is a Blazer tank. With a 41 gallon, you are dragging around a BUNCH of weight you don't need to haul or you have a lot of air space in a partially filled tank which encourages condensation and corrosion.

So by all means, go to a rear mount tank. Just do a Blazer tank.
(My own truck has the in-cab tank still. I like having the spare tire under the bed option...)

DarkFlounder · 01-23-2015, 08:29 PM

My 72 has already had the in-cab tank removed (PO put subwoofers in its place).

Yeah, 41 gallons might be overkill. I do want to get rid of the crappy plastic 16gal saddle tank the truck currently has.

I'll look into the Blazer tank, thanks.

Lees68GMC · 01-23-2015, 09:10 PM

I think there's some confusion here, the Suburban tank is 21 gallons not 41 and its a side fill so it not only fits between the frame rails perfectly with plenty of ground clearance, you can also place the fill on either side of the truck easily. Mines a Vortec 5.3 motor there's 5 of these trucks (all Vortecs) with the very same tank set-ups Tims done at the local Hot Rod shop and they all, work great. Hope it helps.

Daman · 01-24-2015, 08:53 AM

Ok what parts did you use for the filler neck Lees68GMC?

That's pretty close to what I want to do

01-23-2015, 08:12 PM	#1
DarkFlounder Registered User Join Date: Nov 2014 Location: Austin, TX Posts: 281	Gas tank and exhaust routing Sometime this year, I'm gonna replace the bed (eventually, the rust will stop holding it together), and while I've got the bed off, I'll probably put in a new under-bed gas tank. I really like the 41gal Suburban tank between the frame rails I saw another post about. Without having climbed under and measured the space, would a tank this size be better placed forward or behind the axle? And since I'm eventually going to have the exhaust redone (about as many holes and rust as the bed), I'm thinking about having the exhaust routed outside the frame rails (so they'll not be directly under the tank) and dumping out in front of the wheels. Any thoughts? Should I stop thinking about the truck and get back to work (it's Friday after 4pm, leave me alone). __________________ 72 K2500 Sierra Longbed Wideside 350/TH350/NP205 66 Plymouth Barracuda 225 Slant6

01-23-2015, 08:24 PM	#2
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,715	Re: Gas tank and exhaust routing Get back to work! Just kidding, it is Friday. IMO, the Suburban tank is just too big. And there is no way to put it in front of the axle. If you want to ditch the in-cab tank, the best solutions is a Blazer tank. With a 41 gallon, you are dragging around a BUNCH of weight you don't need to haul or you have a lot of air space in a partially filled tank which encourages condensation and corrosion. So by all means, go to a rear mount tank. Just do a Blazer tank. (My own truck has the in-cab tank still. I like having the spare tire under the bed option...) __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

01-23-2015, 08:29 PM	#3
DarkFlounder Registered User Join Date: Nov 2014 Location: Austin, TX Posts: 281	Re: Gas tank and exhaust routing My 72 has already had the in-cab tank removed (PO put subwoofers in its place). Yeah, 41 gallons might be overkill. I do want to get rid of the crappy plastic 16gal saddle tank the truck currently has. I'll look into the Blazer tank, thanks. __________________ 72 K2500 Sierra Longbed Wideside 350/TH350/NP205 66 Plymouth Barracuda 225 Slant6

01-23-2015, 09:10 PM	#4
Lees68GMC Registered User Join Date: Jul 2013 Location: Prescott Arizona Posts: 343	Re: Gas tank and exhaust routing I think there's some confusion here, the Suburban tank is 21 gallons not 41 and its a side fill so it not only fits between the frame rails perfectly with plenty of ground clearance, you can also place the fill on either side of the truck easily. Mines a Vortec 5.3 motor there's 5 of these trucks (all Vortecs) with the very same tank set-ups Tims done at the local Hot Rod shop and they all, work great. Hope it helps. Attached Images __________________ 68 GMC SWB Vortec 5.3 98 Chevy Blazer ZR2 94 Mazda Miata, LS2 6 speed, sold "No matter what happens, nobody gets out alive"

01-24-2015, 08:53 AM	#5
Daman Registered User Join Date: Jan 2014 Location: Billings Montana Posts: 183	Re: Gas tank and exhaust routing Ok what parts did you use for the filler neck Lees68GMC? That's pretty close to what I want to do

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.