1966 Gran Sport fuel tank question

Discussion in 'Repro Parts' started by Devin, May 3, 2020.

  1. Devin

    Devin Buick guy since 1982

    Hi guys and gals. I have a 66' Gran sport that has been sitting so long the fuel smells like varnish. I don't know if it is the original but want to know what brand replacement tank has the best quality for the money. I have seen fuel tanks on Ebay from $99 to $600. I was hoping someone has some experience in this parts from American to China markets out there. Thanks.
  2. 70skylark350

    70skylark350 Well-Known Member

    I am looking for a replacement tank as well, for my 70, also new sending unit, tank straps, and hardware. I was looking at OPGI, they have different options depending on your budget. I would also like opinions on quality.
  3. GS Spoken Here

    GS Spoken Here Well-Known Member

    As I remember, the tank I purchased for my 66 GS was one without a neck. Could not find one with a neck for 66, with correct vent placement. I compared a 65 and 66 GS and tanks and the difference was the neck, you can get a 65 with the neck, not 66.
    Devin likes this.
  4. philbquick

    philbquick Founders Club Member

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  5. 64 skylark mike

    64 skylark mike Well-Known Member

    I ordered a Spectra Premium from The Parts Place for my '64. It fit perfect and looks great. It was $199 with free shipping. Only complaint I have is the collar on the end of the filler neck is off degreed, so the gas cap doesn't set straight. Definitely a quality tank! I got the new straps from In Line Tube. New tank pad from pglade here on the board, also quality!
    The only 66 tank I could find from Spectra Premium doesn't have the filler neck. Bummer
    Devin likes this.
  6. TrunkMonkey

    TrunkMonkey Well-Known Member

    I have put Spectra EFI tanks on both my '64 and '68 'larks.

    The '64 filler neck was badly bent in shipping, and the '68 cap degree being off bothered me.

    On the first, some hammer love, and MAP gas torch fix that, and the MAP torch and a twist fixed the clocking for the cap.

    Easy enough to resolder them.

    If the '66 neck is the same length, but the angle is off, it might be an easy fix.

    Or simply desolder and move the filler to the new tank.

    Take measurements from the old tank to get the angle.

    And fill the old tank with water almost to the neck/tank join, then use a MAP torch to remove it. Transfer to new tank, solder it in, and adjust it as needed.
    Devin likes this.
  7. 64 skylark mike

    64 skylark mike Well-Known Member

    I didn't have any damage on mine from shipping. The cap not setting straight bothers the crap out of me, but the tank is very well made. I wish I was confident enough to resolder the cap mounting piece like Trunk Monkey did, but the idea of trying that scares me more than the crooked cap bothers me haha!
    Devin likes this.
  8. jonmil

    jonmil Well-Known Member

    Devin look into tank GM 37G its listed as 66-67 oldsmobile but is correct for 1967 gs cars. I put one on my 67 GS 400 last year and it fit perfectly and had the correct 2 vents in the upper left corner. Check yours to see if you have the same 2 vents and your good to go plus it has the filler neck and was less than $200 shipped to my door.
    Devin likes this.
  9. TrunkMonkey

    TrunkMonkey Well-Known Member

    If the tank has never had fuel, it is really easy.

    Desolder the end piece.

    Set the end piece in place and correct orientation setting it on the ground, flat and square with the tank above and resting on the filler tube. (think "headstand").

    Then apply flux to the parts with a brush, set the torch flame to the tube/end piece, and start feeding the solder to the joint. It will flow and fill quickly, then pull the flame away and either use a spray bottle of alcohol to cool, flux brush loaded with flux or even a bit of water to quench.

    The biggest issue is trying to do a neck to tank join and getting a lot of solder into the tank, (and then trying to get it out).

    If you put too much heat in the join, the solder may "drain" from the join. You need to "play" the heat on the join area and be able to "pull off" as the flow starts.

    If you mess up, you can just start over, you really won't hurt anything. The biggest issue will be removing the "drained" solder.

    What I do, is use a length of rubber hose inserted and taped to a shop vac hose to vacuum out the tank. A mirror and flashlight to help position the tank and get the solder slag in a corner to remove.

    It is not difficult but takes a little effort and persistence.

    Just remember, if the tank has had fuel, it is best to fill with water as much as possible, and as close to the area you will solder. You want to prevent a large cavity of potential fumes, but also have enough distance so the water does not absorb/quench the heat at the join area during soldering. (harder to explain in text, versus showing in actual application).

    I have done the same thing on radiator tanks, inlet/outlet tubes, cap ends, and the coolant/drain bungs. (but I also have done Heating/cooling systems and plumbing, much the same techniques).

    Heck, if a monkey can do it, anyone can.

    I hope that helps. :)
    Devin likes this.
  10. Devin

    Devin Buick guy since 1982

    Thanks guys. That's some good knowledge about the interchangeable parts and soldering of the filler. I think the GM 37G will fit the best. I'll be checking the vents to make sure.
    TrunkMonkey likes this.
  11. wkillgs

    wkillgs Gold Level Contributor

    The GM 37G has the vents by the back bumper, which isn't correct for a '66.
    The GM 37A has a vent in the proper location.... on the passenger side at the front. The GM 37D has no vent. Neither has the filler pipe tho.
    I scored the 37D on Amazon for $92, so I jumped on that one. The filler and vent pipes are gonna take extra work to get it correct.
    There are a few options as to which pn to go with, none are perfect for a 66..... either there is no filler neck, or the vent is missing or in the wrong place!
  12. gs66

    gs66 Silver Level contributor

    I put a Spectra 65 GS tank on my 66 just to avoid the no neck hassle.
  13. GS Spoken Here

    GS Spoken Here Well-Known Member

    I compared a 65 Spectra GS tank and a original 66 GS tank, an the only difference, was the neck. Jim did you have any problems with the65 tank neck clearing the rear crossmember or having the gas cap hitting the license plate holder? DSC03443.JPG DSC03444.JPG

    Attached Files:

  14. 66GSconv.

    66GSconv. Well-Known Member

    I but in the spectra GM37G the vent tubes were in the correct place has the filler neck and fit like a dream, they tried to get me to order a stainless steel model but stupid me said no give me the galvanize' wish like hell I got the stainless
    70skylark350 likes this.
  15. gs66

    gs66 Silver Level contributor

    I encountered no clearance issues.
  16. B-rock

    B-rock Well-Known Member

    I have a good condition original 65 gas tank if you are interested. Located in vancouver wa.
  17. Devin

    Devin Buick guy since 1982

    Thanks B-Rock, but I'm going to get the 65 Spectra tank. I can get it through the O rileys auto parts.
    B-rock likes this.

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