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Old 12-26-2005, 07:23 PM   #1
68chevylwb
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Location: Bakersfield, CA
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brakes

has anyone seen a 68 chevy truck 3/4 2wd with rear drums 12 inch not 11 inch has rear leaf springs and is a custom camper
having trouble with rear brake adjust assy.
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Old 12-26-2005, 08:00 PM   #2
Longhorn Man
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Re: brakes

is it a big block?
Does it have the Eaton HO52 rear end, or the Dana?
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Old 12-26-2005, 10:47 PM   #3
ChevLoRay
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Re: brakes

GM offered different diameters of drum brakes; but you had to buy the right truck to get the larger sizes. C10's had 11x2-inch drums all the way around, while C20's had 11x2.75 inch drums. K20's had 12x2-inch. C30's had 11x2.75-inch drums in front, and 13x2.5-inch drums in back.

Early Classic Enterprises offers an 11x2.75-inch conversion to replace the 2-inch wide rear drums, if you want to go that route. It is essentially the 3/4-ton rear brakes on a 1/2-ton axle. Pull the axles and backing plates with brake parts attached. Install new backing plates and axles and new brake parts and get more braking power. Based on brake lining area in square inches, you'll jump from 83.5 square inches (rears) to 119 square inches (rears). If you have discs on the front, overall braking should be greatly enhanced.

But, to answer your question, I don't find a 12-inch drum listed in my '69 Truck Data Book. GMC? Could be different. But, the leaf springs were an option on the Chevy's and there was nothing noted to indicate that the drum brake diameter would be different. However, anything is possible in a world where there is interchangeablity of parts. I wouldn't be surprised if somebody put a FoMoCo rear end under one of our trucks!!! Yeah....gimme a good 9-inch rear end, with some 5.38's and.....a big ole pocket full of gas money.....
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Old 12-26-2005, 11:36 PM   #4
Robert1970C20rstbukt
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Re: brakes

The dana rears have 12 x 2 1/2" brake shoes and the eaton has 11 5/32 x 2 1/2" shoes I think. I found a listing in my '69-'70 truck parts book, it lists 12 x 2 1/2" brake shoes for a C20 with the Dana axle, that's probably what you have.
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Old 09-11-2013, 01:04 AM   #5
smonroe72
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Re: brakes

where can I buy the 12 inch drums and shoes
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