Disc Brake Conversion Recommendation

Discussion in 'The whoa and the sway.' started by 1968_GS400, Sep 18, 2021.

  1. 1968_GS400

    1968_GS400 Founders Club Member

  2. jaye

    jaye Well-Known Member

    I used Buick disc brakes on my 69 and wilwood calipers, dual pistons which bolted right on. 68-72 skylark disc all will fit
    1968_GS400 likes this.
  3. Jeff Pulera

    Jeff Pulera Well-Known Member

    I went with the Upper/Lower kit from Inlinetube.com which included master cylinder and vacuum booster, proportioning valve, spindles, rotors, calipers, pads, hoses, caliper brackets and backing plates. The works! They also offer perfectly fitting computer-bent lines and I went with their stainless steel lines front to rear. This kit used the stock-style rotors and calipers like you will find on an original 70-72 with discs, so any wheel should fit. If you get into the "big brake" kits you may find your wheels no longer fit!

    Attached Files:

  4. FLGS400

    FLGS400 Gold Level Contributor

    I went with the CPP front only kit for my 69. Bought it from OPG last year during one of their Black Friday specials (discount and free shipping). It is very similar to the Inlinetube kit that Jeff mentioned above. I don't really have any feedback though, as it took 5-months to come in and I have not had time to install it yet.

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  5. 1968_GS400

    1968_GS400 Founders Club Member

    Thank you!
  6. 1968_GS400

    1968_GS400 Founders Club Member

    Thank you!
  7. 1968_GS400

    1968_GS400 Founders Club Member

    Thank you!
  8. 1968_GS400

    1968_GS400 Founders Club Member

    Hi Jeff,

    Thanks again for your comments.

    Is this what you got? DBK6807.

    Did you leave drums on the back? It looks like their rear kits are for 15 inch or larger wheels.

    76153D1B-1EDF-411D-BE8E-307EC33B1420.jpeg 5910EFE6-D534-4A78-BA62-B281B951CA2B.jpeg
  9. gs430

    gs430 Well-Known Member

    In the late 80's i pulled calipers, rotors, spindles, booster, master cyl and proportioning valve from a 70 Olds Vista Cruiser. Worked fine,.. But, if you are replacing spindles you might look into doing the tall spindle conversion with tubular upper control arms. Turned my '70 convertible from a barge into a flat handling yacht. So much so that the vinyl bench seat is the limiting factor in cornering, sliding around on the seat adds that extra dimension.
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  10. stump puller455

    stump puller455 1970 GS 455

    I did the c5 Vette 4 wheel kit from ccp the worst tech support on the planet…
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  11. 1968_GS400

    1968_GS400 Founders Club Member

    My wheels are 14 inch. So far, I found:

    1) InlineTube DBK6807 but it's currently not in stock


    2) CPP M1790DX from OPG but it's current not in stock

    *Says must use on 15 inch wheels or larger so maybe don't fit? But these were the ones mentioned by Rich above


    3) CPP CH28814 from OPG (In Stock)

    *Says works on 14 and 15 inch wheels'
    *Drops front end 2 inches


    4) Right Stuff AFXDC14

    *Says works on 14 inch wheels



    I think I am leaning toward the InlineTube DBK6807 or the Right Stuff AFXDC14.

    Let me know if anyone has any comments especially about the Right Stuff kits.

    Thanks again for all the comments and feedback.
  12. 1968_GS400

    1968_GS400 Founders Club Member

    I think I have settled on the Right Stuff AFXDC14 mainly because they are in stock.


    However, it comes with a 9 inch power boost. It looks like my 68 GS 400 has an 11 inch on it for the factory drum brakes.


    Does anyone know what it came with originally and the part number?

    The Inline kit has an 11 inch power boost.
  13. Clarkie

    Clarkie Well-Known Member

    I have a kit from The Right Stuff and it came with an 11” booster.
    1968_GS400 likes this.
  14. Clarkie

    Clarkie Well-Known Member

    RSD-AFXDC06C Was the kit I got.
    1968_GS400 likes this.
  15. 1968_GS400

    1968_GS400 Founders Club Member

    Perfect! Not sure why Right Stuff doesn’t have those listed on the 14 inch wheel page.


    Thank you!
  16. Clarkie

    Clarkie Well-Known Member

    You might want to double check this works for 14” wheels. I have 15s. I think this kit will work, though. I got it from Summit.
    1968_GS400 likes this.
  17. 1968_GS400

    1968_GS400 Founders Club Member

    The Right Stuff page and Summit Racing page say they work for 14". However, they are listed under the 15" Street Series on the Right Stuff page, which I guess is why they aren't on the 14" page.

    I ordered. I'll reply back once I get them on, but I think they will fit.
  18. pbr400

    pbr400 68GS400

    If the kit uses standard GM ‘69 and up calipers, the companies may exclude 14” wheels because SOME factory 14” wheels won’t work. My GS has drums and came with steel wheels and full wheelcovers. I tried to borrow those wheels to move a ‘74 Firebird but the caliper hit the center section of the wheel. I grabbed a set of 14s from my G body El Camino and they fit fine. (Problem wasn’t wheel diameter, it was shape of the center).
    So…if you’re using rally wheels you should be ok. 1968 factory steel wheels may not work.
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  19. 1968_GS400

    1968_GS400 Founders Club Member

    Well, I am glad I took Brad's advice and called. Right Stuff says for sure the AFXDC06C won't fit the 14-inch wheels, so they cancelled my order.

    They recommended the AFXWK14 kit (which is the same kit as the AFXDC14 but without the upper assembly) and the G10030971 upper assembly if I want to do the 11-inch booster.



    Total price: $655.20 which is a little less than the AFXDC06C.

    They did mention there still could possibly be an issue with the callipers as Patrick said, even with the 14-inch kit, but hopefully, it will be ok.
    Clarkie and Max Damage like this.
  20. Clarkie

    Clarkie Well-Known Member

    Right on. I look forward to hearing how it works out for you in the end.
    1968_GS400 likes this.

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