40 Gallon squarebody gas tank... wil it fit?

[Nitis]

AS I get closer to assembling my list of things to acquire to do my LS swap I come to a cross roads with the fuel tank. I want to go inside the frame rear style for sure. Budget wants me to use a square body style which means some fab work to the cross rails under the bed no big deal.

I have a long bed so will a 40 gallon fit? the 25 just seems dainty and the 31 would be ok but why not a 40?

Any other suggestions?

[Jake1971]

Member Davemotohead did this to his 1971 4x4 LWB truck.
http://67-72chevytrucks.com/vboard/s...d.php?t=551269

[Nitis]

is that a 40 or 31 it came out of a blazer he called a suburban

if its a 31 my guess is the 40 will be too long and up over the punkin

[MAC71]

I have the 31 gal tank from a 88 blazer/suburban. It fits well. If you have the differences in size between the 31 and 40 gal I could do some measuring as my bed is currently off.

[Nitis]

Per LMC

25 28.75x28.125x10.75
31 29.75 x 28.125 x 12.75
40 35 x 28.75 x 13.125

I like the depths of the 25 but the extra fuel would be nice!

[MAC71]

ok, my tank is not in the truck but I will lift it back in tomorrow for some better measurements, but got a tape measure out tonight and if the 40 gal tank is really 35 in long its going to go past the back of the frame rail, but that is with a coil spring truck. If you have leaf springs than the measurements may be different. With the 31 gal tank I have the rear cross member all the way back and there is about 3 in of frame left behind the cross member.

[Nitis]

Ever get a chance to take some measurements Mac?

[MAC71]

Originally Posted by Nitis

Ever get a chance to take some measurements Mac?

I took the frame to the sand blasters on Monday. Forgot to measure. I should be getting it back mid next week.

[Nitis]

No problem thx

[1972RedNeck]

I couldn't get the tank back far enough to get as much diff clearance as I wanted. If I would have built a new cross member I think it would have fit though.

[MAC71]

I do have a few photos of the 31 gal tank in the frame rails.

[BigRed76]

I just went out in the garage and measured my 4wd frame and 35" back from the rear of the frame rails is right at the rear diff. cover, so with the crossmember moved all the way to the rear of the frame 35" would be right about at the mounting surface of the rear diff. cover. So I'd say it would fit only if the truck is lifted at least 4 inches, otherwise that tank will hit the top of the rear diff.

[MAC71]

Heres a newer pic of the 31 gal tank.