What years & cars had 11" x 2 1/2" finned rear brake drums. Thanks.

My 66 Dodge Coronet 9 passenger station wagon had 11" finned rear drums, don't know if they were oem or not though. The car came to me with 125K miles from its original owner. It had a factory trailer towing package on it, including a 3500lbs welded on hitch, a 318 Poly, 727 with additional cooler, 11" brakes, front sway bar, and a 3:23 sure grip 8 3/4" rear. The car was purposely purchased to tow a camping trailer. Came to me with all the original documentation and all its dealer service receipts for its 1st 80K miles. too bad it was in such bad shape by then.

I grabbed some big rear drums off of a station wagon in a wrecking yard to bolt on Dana 60 under my Coronet. That was a long time ago but I'm pretty sure it was a B body wagon. Suppose it could've been a C body. Those brakes were killer. I lost brake power when I swapped them out for disc brakes.

My 66 Hemi with Dana came with those, non power brakes. Back in the day I parted out a 68 and 69 440-Dana cars and they both had the finned brakes.

Incorrect & erroneous tech info deleted, with apologies.

the 11x2 1/2" drum setup came on pickups, C-bodies, wagons and most [if not all] B-bodies with the trailer towing package.
8 3/4, 9 1/4, and dana rears will all interchange, from roughly 66 up to [at least] the 78-80 model year and perhaps farther, with the 4 1/2" bolt pattern.
the axle stand off is the same, so all you need is the backing plate, drums, and the associated hardware.
be aware you also need the e-brake actuating bar as well, as the bar for the 10" brakes is shorter.

the imperial drum will not work, as the bolt pattern on those was 5x5". i'm not 100% sure, but i "think" the backing plates will work, providing they are for 2 1/2" shoes.
when swapping to the 11" drums, most [if not all] the difference in width is offset inward, thus not affecting the width of the rear in question.

Cop Spec M bodies had 11x2.5" finned drums. You can still buy them new

Go to local store, or Amazon will deliver for $60

RAYBESTOS 2953R

Good to know!

I have the same setup and was back and forth about changing to discs for weight reduction!

Mine came off a 300 C-body.

As always now, be ready for crappy quality with non OEM stuff. I was replacing the factory 11"x 2 1/2" finned drums on my '89 Diplomat Police Package and ordered a set of Raybestos from Rockauto. They were so out of round out of the box that when I tightened lug nuts and it pulled the drum in, the rear wheels would barely even turn. So much Chinese junk. I would've had to find someone to turn them which isn't easy anymore, or ship them back to rockauto at my expense. I ended up junking them and buying a NOS set. Expensive but I get 75,000 miles or more out of a brake job and the NOS ones were perfect.

I also have a few drums the same size but no cooling fins.

Don't really know if the fins on the drums really make that much difference or not, but they sure look cool.

My 1970 charger with the 4 speed and dana has 11x2.5 rear finned drums, and 11x 3 drums up front. I think your off a 1/2 inch.

Y'know what, I was totally wrong - 11x3 and 11x2.5 is correct.
I'll edit my off-the-cuff and incorrect reply, and thanks for the correction.

imperial backing plates will work.But as stated the drums will not as they are larger bolt pattern.

Thanks for all the great answers. I have two more questions.
Is there a casting number and date code on these?
What is the largest diameter that these can be turned to?

I thought my rear brakes were 11 x 3 for a long time because the drum is more than 3 inches wide. But when you measure the shoe you see that the friction material is only 2.5 inches wide. The drums are extra wide since they have an inner lip which is supported by the fins. Those drums are heavy. I used have a small stash of original drums that I kept around just in case I needed a spare. Finally got rid of them after I switched to disc brakes.

Two demerits

Ouch, this is one tough crowd.