fuel tank to small

[1971k567cam]

So I was thinking that I would like to put a bigger fuel tank in blazer this one seams to run out very quick. I am in process of building a 383 mpfi engine with a 70r4 set up to put in but have found with carb that fuel goes really quick after 4.10 gears. Would a suburban tank fit in a blazer? Same sender? Thanks for all your help and ideas

[70cst]

ttt for assistance

[turp mcspray]

I put a 31 gal tank from a 73 up blazer, in my 72. I moved the rear crossmember back. And used the front crossmember from the 73 up tank. Sender is still o-90 ohms. I also relocated the filler neck to the driver side, so I could attach it to the original filler.

[Gary 70 Jimmy]

If I put a bigger tank in my jimmy then my wallet would be to small.

[cleszkie]

I put in a 40 gallon tank made by NMP (Northwest Metal Products). Cost about $300, but that was like 15 years ago. Came with fuel sender that works with stock gage. When I fill that thing up, the Blazer squats!

[themb2g]

that same tank from NWMP.com Is about $700 now. but it is 37 gallons, which is nice. I am thinking of getting one, but i need to have them install an intank pump capable of 65 psi for efi into my lq4.

[mcmlxix]

Bringing up an old thread.... contemplating the LSx upgrade...

I was looking on www.rockauto.com at 1991 Suburban 40 gallon tanks. They use an in tank pump to support the 454 TBI motors, but not sure of the pressure the pump puts out. You can always upgrade to a Walbro pump. They list dimensions for the 31 Gallon andthe 40 Gallon tanks. You can get a 40 gallon tank and sending unit with pump for $230 plus S&H.... you just need a regulator, probably the C5 Corvette regulator would work well....

Has anyone tried to shoe horn the 40 gallon tank under a Blazer?

[turp mcspray]

IIRC, the only dimension that changes with the 40 gal. is the length from front to back. I don't think there is any way it will fit in a blazer. With mine I moved the rear crossmember further back, and the front of the 31gal. tank, goes right up to the differential.

[Firebirdjones]

Originally Posted by mcmlxix

Bringing up an old thread.... contemplating the LSx upgrade...

I was looking on www.rockauto.com at 1991 Suburban 40 gallon tanks. They use an in tank pump to support the 454 TBI motors, but not sure of the pressure the pump puts out. You can always upgrade to a Walbro pump. They list dimensions for the 31 Gallon andthe 40 Gallon tanks. You can get a 40 gallon tank and sending unit with pump for $230 plus S&H.... you just need a regulator, probably the C5 Corvette regulator would work well....

Has anyone tried to shoe horn the 40 gallon tank under a Blazer?

This subject seems to have popped up alot lately. I too want a larger tank, but I also want an internal fuel pump for the 6.0 swap I did rather than the current external.
I'm really leaning towards a custom aluminum tank. I would rather have the tank hang lower rather than get wider/longer. Or maybe a mix of the two, but I definately don't want to start moving cross members and hacking up the frame, because I'm also installing a hidden hitch, so moving the cross member is out of the question really.

Just so you know, LS engines require 55 psi minimum to run properly.

[viking427]

Someone over on CK5 just got a NWMP 37 gallon tank and posted some pics of it and their 72 Blazer install. You can clearly see the Blazer's rear crossmember that would need to be moved back or removed trying to wedge a 40 gallon Suburban (1991, EFI, internal pump) tank in there. The burb tank is 35" long x 29" wide x 14" deep. As Turp says he had to move his rear crossmember back just for the Blazer/Burb 31 gallon size (29" x 29" x 13" deep). However, if you're running a class III/IV/V trailer hitch, you could probably remove the rear crossmember altogether, since that would provide the critical crossways frame support, assuming it was installed permanantly.

http://coloradok5.com/forums/showthread.php?t=24981

[Firebirdjones]

Looks like that tank installed without moving the cross braces, and I also see a hitch in there as well. Looks like what I want to do will work.
I'm using the hidden hitch from Earlyclassics. I believe it would be a class III more than likely.

Unfortunately some of those guys posting did this swap 10 years ago or so, and someone mentioned these particular gas tanks aren't stocked anymore.
So I'm guessing it's a custom order basis (if you can still get them) or someone has done this more recently??

[viking427]

Yes the NWMP 37 gallon and Aero 40 gallon (almost identical) are both still produced and have support (parts, install kits etc.). Correct, niether one of those tank will require moving crossmembers since they were specifically designed to fit the early Blazer. Aero actually lists theirs, p/n 1139, as fitting 70-85 Blazer. However, the 31 and 40 gallon GM oem tanks that came in 73+ Blazer and/or Suburban are basically square or rectangular in shape. These oem tanks lack the "drop" at the rear designed into the NWMP & Aero tanks to go under the crossmember, which means the crossmember needs to be moved back when using the larger oem tanks in order to allow them to fit. The attraction of these oem tanks for those doing EFI swaps (besides their extra capacity), is the later ones (88-91?) are setup for fuel injection with the necessary plumbing and in-tank electric pumps. I'm not sure if the sending unit holes in the NWMP or Aero tanks are large enough to drop an electric pump setup in them or not, I would think so.

http://www.aerotanks.com/inventory/1139.html

http://www.nwmp.com/index.php?option...-gmc&Itemid=17

[AJs72K5]

Originally Posted by turp mcspray

IIRC, the only dimension that changes with the 40 gal. is the length from front to back. I don't think there is any way it will fit in a blazer. With mine I moved the rear crossmember further back, and the front of the 31gal. tank, goes right up to the differential.

Not entirely true. There are several folks around that have put a NWMP tank into a K5. Burt4x4 on this board is currently running one. Was a direct bolt in, if I recall.
Posted via Mobile Device

[viking427]

Originally Posted by AJs72K5

Not entirely true. There are several folks around that have put a NWMP tank into a K5. Burt4x4 on this board is currently running one. Was a direct bolt in, if I recall.
Posted via Mobile Device

He's talking about the factory 31 and 40 gallon tanks GM put in the later Blazers and Burbs

[Firebirdjones]

Originally Posted by viking427

Yes the NWMP 37 gallon and Aero 40 gallon (almost identical) are both still produced and have support (parts, install kits etc.). Correct, niether one of those tank will require moving crossmembers since they were specifically designed to fit the early Blazer. Aero actually lists theirs, p/n 1139, as fitting 70-85 Blazer. However, the 31 and 40 gallon GM oem tanks that came in 73+ Blazer and/or Suburban are basically square or rectangular in shape. These oem tanks lack the "drop" at the rear designed into the NWMP & Aero tanks to go under the crossmember, which means the crossmember needs to be moved back when using the larger oem tanks in order to allow them to fit. The attraction of these oem tanks for those doing EFI swaps (besides their extra capacity), is the later ones (88-91?) are setup for fuel injection with the necessary plumbing and in-tank electric pumps. I'm not sure if the sending unit holes in the NWMP or Aero tanks are large enough to drop an electric pump setup in them or not, I would think so.

http://www.aerotanks.com/inventory/1139.html

http://www.nwmp.com/index.php?option...-gmc&Itemid=17

Great information. Unfortunately the Aero tank has a side note listed that hitches may have to be removed.
Not sure I want to take that chance even with the price being half as much.

The NWMP tank is twice the cost but pictures show it being installed with a hitch in place. I just wonder what is so different between tanks that makes the hitch an issue with Aero? If it's a simple solution or takes mild fab work, I'd go with Aero and cross my fingers.

[viking427]

I think thats just a standard disclaimer to cover themselves for hitches whipped up by "Bubba's custom hitches" that unnecessarily take up 5 sqft. of space under there. I'd take the Blazer to a local (reputable) hitch place and have one built or modified to fit your vehicle once the big tank is in there. You'll get a better fit, exactly what you want and how you want it done at such hitch shops, usually for same or not much more $ than mail order hitches.

[Firebirdjones]

The Hitch I'm getting is the "hidden" hitch sold by Earlyclassics.com that is made specifically for these body styles.
How much room it takes up however I'm not sure. It hides behind the license plate.

I'm sure any minor clearance issues I could deal with so long as I don't have to completely re-engineer the thing

I'll have to call both Northwest Metal and Aero and talk specifics and make a decision I guess. I really appreciate the info, many thanks.

[turp mcspray]

Here are a couple pics of a 73 up, tank installed. The rear crossmember was moved back 8". It's not a great shot of the front of the tank, but it goes pretty much up to the rear diff. I have seen this install done on a non lifted truck, and if you can remove the diff cover with out raising the rear of the truck, it isn't by much.

[NW_Ryker]

I have a NWMP fuel tank in my truck, and the trailer hitch had to be removed to install it.

[viking427]

Hmmm, that 31 gallon Blaz/Burb tank does look tight in there, doesn't look like there's an extra 6" of frame left on the backside that the 40 gallon Suburban tank would need, regardless of the crossmember. It does look original though, I like the factory skid plate setup.