11 Inch Rear Drums?

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jar84203

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I have a 71 Duster 225 slant six with a 73-76 front disc brake disc conversion and the rear has been converted to the large bolt pattern. I was under the impression that the rear drums would either be 9 or 10 inch, but upon inspection it turns out they are 11 x 2 1/2. My question is what vehicle might the rear brakes be out of so that I know what parts to order. The rear end was also swapped out for a 8 1/4 even though slant sixes came with 7 1/4. Thanks.

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Cordoba, '79, big block or HD brakes or tow package.
 
jar84203 said:
I have a 71 Duster 225 slant six with a 73-76 front disc brake disc conversion and the rear has been converted to the large bolt pattern. I was under the impression that the rear drums would either be 9 or 10 inch, but upon inspection it turns out they are 11 x 2 1/2. My question is what vehicle might the rear brakes be out of so that I know what parts to order. The rear end was also swapped out for a 8 1/4 even though slant sixes came with 7 1/4. Thanks.
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Are you sure you have a 8 1/4" (inspection cover) and not a 8 3/4" (3rd member type)? Most likely someone did a 73-later A-body swap if its a 8 1/4". Probably from the same car the front brakes are from. The 8 1/4" were the rear ends on 73-76 A-bodies with the 340-360 engines and are direct bolt-ins. I've seen them in Aspens & Volare wagons and 360's but don't know the width. Those had different leaf spring pads. You could even have a 9 1/4" rear but I doubt it since they would be wide. The 8 1/4" A-body rears had 10X2 1/2" brakes. You might want to measure the diameter again. Those rear ends had the similar shape backing plate flanges as the 8 3/4" and Dana's but only had 4 bolts.

Maybe someone out there can give some input if brakes from a 9 1/4" rear will bolt up to the 8 1/4" rears since they were used on larger cars.
 
The 11 x 2.5" LBP brakes on a 9.25 are the same big brakes that were used on the 8.75 and Dana rearends and they will bolt right uo to an 8.25 as well. You will just use only 4 of the mounting holes instead of all five.

Those brakes can be found on C-Bodies, Hi-Po, BB B and E-Bodies, 3/4 and 1 ton trucks and later B-Bodies like the Cordobas, Magnums etc.

Joe
 
It's an 8 1/4 rear and the diameter of the drums are 11 inches. It says on the drum max diameter 11.090.

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Just found out the parking brake cable is missing. Would it matter what cable I buy or does the 11 inch require specific cables?
 
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