11 Inch Rear Drums?

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.

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.