1970 Buick GS 455 Frame

Discussion in 'Buick FAQ' started by bernhard, Dec 28, 2017.

  1. bernhard

    bernhard Active Member

    Is the Buick GS 455 frame different from the 1970 skylark frame?
    If there are different how do they differ?
    Can a 1970 skylark frame be converted into a 1970 GS frame?
  2. DBS

    DBS Well-Known Member

    Lots running 455's on 350 frames and a simple change of the motor mount pads will allow this, but technically the front 455 frame horns are thicker metal so yes, they are different and no, you can't convert them.

    BUQUICK I'm your huckleberry.

    While there may be some differences, they will interchange with no modifications required except for the big block engine mount pads.
  4. bernhard

    bernhard Active Member

    Thanks for the reply's.
    Is the 1970 GS 350 the same as the GS 455 frame?
  5. Bernhard,

    The GS 455 frame differs from the GS 350 frame that is shared by the Skylark.

  6. Rich Johns

    Rich Johns Platinum Level Contributor

    1970 Buick GS 455-GS Stage 1 frames are unique.

    They are stamped BW on rear frame rail.

    The C channel thickness of metal between firewall and where lower control arms bolts into frame is 50 thou thicker than any other Frame used in any other A body car in 1970.

    The front cradle in front of firewall and rear section housing rear axle to the back crossmember is standard regular thin gauge metal found on any other Buick or A body frame.

    From my research and observations there are only about 5 stamped dates ranging throughout 1970 model year for these special frames.
    Meaning, a batch of BW frames were manufactured, shipped to assembly plants and gradually used over a period of time.
    Thus, you will have the same dated frame in a range of stamped cowl tag assembly dates.

    I think Buick Chassis engineers were afraid that the torque of the mighty Buick 455 would hurt, twist damage the GS 455 -GS Stage 1 body infrastructure and therefore engineered a Heavy Duty frame for these special Big Block cars in 1970.
    Last edited: Dec 29, 2017
    mrolds69 likes this.
  7. 12lives

    12lives Engage! - Jean-Luc Picard

    Did it carry over into 71-72, 73?
  8. hugger

    hugger Well-Known Member

    It did in 71/72 yes , 73 I have no idea, those cars were kinda beefed up everywhere anyway

    The 70/72 455 frames also have 3 holes in the top of the cradle also whereas the 350's have had st center punched hole

    I also had a Fremont built 70 Skylark with the 3hole frame, only 350 one I've seen with the holes, so maybe it was a plant thing, only Fremont car I've had too so,..
  9. Bigblock71

    Bigblock71 Member

    Why did my picture pop up upside down damn. It’s a 71 btw I put my sisters 72 grille on that’s all I got
  10. Stage 2 iron

    Stage 2 iron 475 IRON HEAD STAGE 2

    How about a 70 GS 455 convertible frame what would the code be would it also be BW ?
  11. TXGS

    TXGS Paint by numbers 70 GS 455 4spd

    I have a 70 GS350 that has the three holes in it as well. It was a leeds built car.
  12. mrolds69

    mrolds69 "The Cure"

    I just looked at my build sheet, in the frame box it says XV43. My car is a Fremont GS455 convertible. For my car, it's XV. It's interesting though, because other make A bodies, the convertible frames are usually boxed. A GS, I thought all the frames were boxed. I'm not sure why a convertible frame would have a different code. But...who knew what Rich said? Maybe there are other differences.
  13. Duane

    Duane Member

    Frank, for the 70-72 years,
    70-72 convertibles were the only frames that were boxed. That is why they carry a different frame number/letter code. Also for convertibles only, the same frame was used by Olds, Buick, Chevy, and possibly Pontiac.

    Also 70 convert frames carry a different number then 71-72 cars.
  14. mrolds69

    mrolds69 "The Cure"

    Thanks Duane! I see...it's interesting stuff about the Buick GS. The extra body mounts in the front, the cross bars, the braces in the rear, and the axle bumper brackets. Now I'm reading about the thicker frame thing that Rich wrote. There's always something new to learn, isn't there?
  15. Stage 2 iron

    Stage 2 iron 475 IRON HEAD STAGE 2

    Thanks Frank and Duane for the clarification this will definitely help this week when I go to check out the car.

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