Hello, I got a decent 8&1/4" rear out of a donor 71 Duster that I am putting in a 68 Dart. It has 11" brakes on it so I'm pretty sure the brakes are not original to a Duster. They are 2" wide. All of the listings I can find for older big cars that have 11" brakes are 2&1/2" wide. Does anyone know what these came off of so I can order new shoes and drums? Thanks!

Look for Duralast PN 334, 68 Fury

I put 2" pads in my 2.5" drums to reduce contact area and help the fromt /rear bias without adding an adjustable tee.

Is it large bolt pattern wheels? No 4" bolt pattern 11" drums .

Where did you measure the drums ? exterior ? or actual inside where the linings press against the drum ???

Its big bolt pattern yes.

Measured them on the inside. I think Raybestos 334PG shoes will work but any 11" drum listing I can find doesn't show a width, or when it does it's 2 1/2". Sounds like the bigger drums would work.

I ended up with some stock Mopar 11x2.5 rear brakes backing plates, the drums measure 3.0 inch inside back several years ago, probably at least ten yrs. ago. I did some research back then and found that the mid 1960 C body came with both 11x2.5 and 11x3.0 brakes on the rear ends
I was planning on running them on the rear of one of my drag cars but never got around to it so maybe it is time to list them on here for sale.
My next new race car will have 4 wheel disc with the biggest brakes I can put on both ends and a parachute, hopefully that I will never need to use 170 to 180 MPH in the 1/8 mile, maybe 220 + in the 1/4 mile

after a few minutes looking in my wagner master catalog, it seems the dodge monaco and polara [C-body] used 11x2 rear brakes as standard equipment from 66 to 76, unless it was a station wagon or had the towing [hd] package, then those got 11x2 1/2" brakes in the rear.
then, the 77 and 78 model years of these got the more common 11x2 1/2 brakes.
if looking for brake parts for your 11x2 brakes, you could start there.

As far as I know the 1970,71,72 A Bodies got 7 1/4 and small bolt pattern. And 8 3/4 and were small bolt pattern as,well. The a Bodies never got 5x4.5 bolt pattern till 73 model year. And lots of 1973 on /6 and 318 cars still got small bolt pattern till they used up what they had
My 1973 Dart came with disk front and 8 1/4 sure grips 321:1 10 inch drum large bolt pattern.
My bet is,someone took a,73 up A Body 8 1/4 and used it in your car with C Body or Truck/Van 11 inch drums as they bolt right on the 8 1/4.
I have snatched up plenty 11 inch drum set ups from C Bodies and Truck / Vans
Just asked for parts from what they ca me off of.

Makes sense, the 8 1/4 has the 11" brakes, big bolt pattern and it came out of a 71 318 Duster. Somebody probably swapped the axles and the brakes at the same time. I don't think the 8&1/2 ever came with 11" brakes in a car. moparx is right, I did find a listing for a Monaco with 11 x 2". Thanks for that. I found shoes but the drums are proving to be not easy to find.

The cop spec M bodies came with an 8 1/4 and 11" drums. But they were 2.5" ones

just did a rock auto check on drums.
a listing for a 67 318 polara found a centric #12363005 drum, except hd/except wagon $54.79ea. [only 2 remaining]
in the info, it stated a friction surface width of 2.600", and no cooling fins.

looking up a raybestos application for the same polara with 11x2 1/2"drums, finds a brake surface width of 2.930", and has cooling fins.

i don't have any 11x2" drums, and the 11x2 1/2" drum sets i have are stashed in a place i would have to dig a while to get to, in order to measure the friction surface.
so take this info for what it's worth, and how much it cost you.