12 Bolt Brake ID Help Needed - The 1947 - Present Chevrolet & GMC Truck Message Board Network

57tailgater · 08-01-2025, 12:20 PM

I have a 12 bolt out of '74 K5 that I am putting into my '57 3100. A long time ago I tore the brakes down to clean things up but in the meantime things have gotten misplaced and I need to get new. I have the drums and they are marked with "GM 333047" and "MAX.DIA.11.24" I see there are two brake sizes listed in most places: 11x2 and 11-5/32x2-3/4. How do I tell what size I need? Where can I get a complete hardware kit that includes the adjusters as well? I am also wanting to get new wheel cylinders too. Thanks for the help!

Pontiac1976 · 08-01-2025, 11:45 PM

E-bay may have complete kit. or RockAuto, LMC online book. if you have the drums, you should see the shoe wear in the drum musers 2" for shoes pad for Reg. or 2-3/4 " heavy duty. (whatever the closes too those numbers just the pad part of the shoes)

08-01-2025, 12:20 PM	#1
57tailgater Registered User Join Date: Nov 2011 Location: Middle Georgia Posts: 335	12 Bolt Brake ID Help Needed I have a 12 bolt out of '74 K5 that I am putting into my '57 3100. A long time ago I tore the brakes down to clean things up but in the meantime things have gotten misplaced and I need to get new. I have the drums and they are marked with "GM 333047" and "MAX.DIA.11.24" I see there are two brake sizes listed in most places: 11x2 and 11-5/32x2-3/4. How do I tell what size I need? Where can I get a complete hardware kit that includes the adjusters as well? I am also wanting to get new wheel cylinders too. Thanks for the help! Last edited by 57tailgater; 08-01-2025 at 04:16 PM.

08-01-2025, 11:45 PM	#2
Pontiac1976 Registered User Join Date: Oct 2015 Location: Ottawa, Ontario, Canada Posts: 803	Re: 12 Bolt Brake ID Help Needed E-bay may have complete kit. or RockAuto, LMC online book. if you have the drums, you should see the shoe wear in the drum musers 2" for shoes pad for Reg. or 2-3/4 " heavy duty. (whatever the closes too those numbers just the pad part of the shoes) __________________ 1977 REG cab Long Bed with a 1984 Front Clip, 82 305 .60 over 9.0.1 flat top pistons, 4bbl, TH350, w/84 SS-intake & cam , w/ 1977 big block rad, 1975 gear box, 1984 master w/ metric fittings top & SAE fitting @ portion block, 1975 3.42 gear open diff. Duel 77-87 Factory air cleaner, duel inlet from rad support . Down sized 9' to new 8' Steel flat bed Was a 77 454 w/308 gear. Taken out 550 lbs. up front with motor clip change.



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