1. PBZ28

    PBZ28 Veteran Member

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    A friend of mine sold his 72 Z28 and is willing to give me a great deal on a set of like new rear brake drums. Could I use them on my 79 Z28? Thanks!
     
  2. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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  3. PBZ28

    PBZ28 Veteran Member

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    Thanks Twisted! Looking at the RockAuto specs the biggest differences are the mount hole diameter ( stud holes ) .453 and .531 and the outside diameter 11.46 and 11.87. The 1979 specs are the bigger numbers. Wondering why, I checked the size of the wheel studs. The only difference is in the width of the threads .4375 and .472 ( knurl diameter - thread diameter ).And again the bigger number is for the 79. But both years use 7/16-20 threads. The center bore is very close at 2.81 and 2.78, but this time the 72 is the slightly bigger number. Both years use the same brake shoes. I’ll try a test fit and post what I find. Thank you for the link!
     
  4. Fbird

    Fbird Veteran Member Lifetime Gold Member

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    you will need to check that center bore diameter as it is what locates the rotor to run true. The only difference I can think of is in 1972 you COULD have a 12 bolt rearend....axles MIGHT be different compared to a 10 bolt
     
  5. PBZ28

    PBZ28 Veteran Member

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    Update: Well the drum seemed to fit ok. Center bore was snug. Will road test tomorrow and let you guys know how it went. Glad I’m giving it a try as I found my adjuster arm not contacting the star wheel. It looks like the heavy gauge wire on the top post/pin is loose because the loop has been widened over the years. Didn’t want to try and bend it until a replacement is available if it breaks. I think some folks call it a z bar due to it’s shape around the wheel cylinder. Thanks for your input.
     
  6. PBZ28

    PBZ28 Veteran Member

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    Did about a 10 mile road test and seemed just fine. Normal brake performance and feel. Will pull the drums in about 50 miles just as a precaution and to adjust the brake adjuster function. Have about a 1/8 inch between the arm and star wheel. Looking for drum rebuild kits that have the Z bar and so far no luck. Was the pandemic the cause of auto parts being scarce now? Maybe a junk yard where you pull what you need may be the best bet now.
     

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