70 GS 4-Speed Transmission Crossmember

Discussion in 'Parts wanted' started by Tom Nesser, Oct 11, 2019 at 8:08 PM.

  1. Tom Nesser

    Tom Nesser Well-Known Member

    Looking for a correct 70 GS 4-Speed Transmission Crossmember for my resto project 1970 GS Stage 1 4-speed. Looks like the one I have is from an automatic car (or different year) as the bolt holes just don’t line up). Plus my MT repro headers don’t clear it (and they always have on the other two 4-speed 70’s I’ve owned. Before we start cutting and fabricating I thought I’d put this out there. Thanks for looking. Tom N
     
  2. turbotimmer

    turbotimmer Stage 1 4 speed

    How do those headers fit around the clutch linkage area?
     
  3. BrianTrick

    BrianTrick Brian Trick

    I have a very nice crossmember that I can send you pictures of tomorrow. Since the 4-speed is in the same location and length as the TH350,should it have the same crossmember?
     
  4. Tom Nesser

    Tom Nesser Well-Known Member

    MT repros -never had any problems or had to modify anything - at least on 70 455 cars. And the sound is like no other, sweet music ...
     
  5. Tom Nesser

    Tom Nesser Well-Known Member

    Please do send pics Brian, so I can see what is different. I don’t know about the TH350 comparison, only that something isn’t right with the one I have now. Car had some other make of headers before that may have fit with this CM. But the MT’s have those monster collectors. CM I have hangs down at least 2-3” lower than the correct original (which easily clears the MT’s. Not sure what I have here. Thank you.
     
  6. BrianTrick

    BrianTrick Brian Trick

    Do you have any pictures of yours,or where the headers are hitting?
     
  7. BrianTrick

    BrianTrick Brian Trick

    ED7B5EE5-DA80-4CF4-AEC7-44A5DAE77541.jpeg 58A5A4D7-A077-4488-B597-590CBBD9FE52.jpeg 1162A9B4-88C4-4631-B01F-9B7C47276F4B.jpeg 5DEA9764-56DB-4D3F-ADC1-CCA8C64C1186.jpeg F91498F4-31D1-4A14-87E5-9C62AD52A26E.jpeg 00CA7B37-7E0F-475A-B701-89BD99934308.jpeg Tom,
    This is the crossmember that I have. One is from a Buick. The other two are the style that I use,but originally came from Cutlass/442’s. I like the way they bolt solid to the frame. I also have the original ends for the Buick piece.
    As far as header clearance,I think they are about the same. I took a few pictures to show that.
     
  8. BrunoD

    BrunoD Looking for Fast Eddie

    Brian,the buick cross member is for a BBB,you can get a little more money for that one, he actually needs a Sbb cross member.notice the hole on the side of the Buick ,that tells you its for a BBB.Bruno.
     
  9. Duane

    Duane Member

    Bruno,
    The slots are in the Olds cross members, which would be for 442's, the Buick one does not have the slot, so it is for a small block.
    Duane
     
  10. Dano

    Dano Platinum Level Contributor

    On my old Stage 1 4-sp. (Brett's black car) the previous owner had to notch the crossmember for MT's. Unfortunately he cut the original BBB crossmember and given that the hole for the brake cable isn't necessary on the 4-sp. cars, but they got the automatic CM anyway & given the condition of the car the ends weren't even pitted, he should've just gotten a TH 350 crossmember. I definitely made him feel pretty dumb about it when I bought the car.
     
    Brett Slater likes this.
  11. BrianTrick

    BrianTrick Brian Trick

    Yea,my Buick crossmember does not have the slot. It came from a GS350,and should be correct for TH350 AND 4-speed.
     
  12. BrunoD

    BrunoD Looking for Fast Eddie

    I saw those 2 round holes,I took it for granted that one was the slot,did not think about the place where those holes where at.My bad.And Brian,I was making yours more valuable .Bruno.
     
  13. Duane

    Duane Member

    The Oldsmobile cross members are so much stronger then the Buick ones when mounted. If the car is not original I always use the Olds or Chevy types.

    I was doing some really great burn-outs in a 71 GSX clone, when I ripped one side of the Buick cross member right out of the car. It appears the one end was real thin and just sheared off. I had grenaded the rear and the torque had to go somewhere. The trans dropped, the engine cocked to one side, the fan was hitting the fan shroud, the whole thing was a mess.

    I understand why Buick set the ends up in the rubber cushions (to deaden vibrations) but..............
    Duane
     
  14. Tom Nesser

    Tom Nesser Well-Known Member

    Thanks for the pics and all the info everyone. I’m going to have to take some pics of the cross member I have to figure what I actually have ... I’ve put MT repros in two other 70 BB 4speeds and never experienced any clearance issues. I’ll put the pic up tomorrow, maybe you can help me figure just what it is that I have. Then we can decide which way to go. Appreciate all the help!
     

Share This Page