11" Rear drum with factory disc brakes

[JG71B]

I did some searching and didn't come up with much. Pulled a complete 8 3/4 rear end, springs and everything out of a doner 71 RT. Somehow I didn't realize it until after I got it home it has 11 inch brakes. My 71 Charger is factory power disc brakes so, will this combination work? Will I need a different master cylinder? Should I just stick with 10" brakes the rear? Appreciate any help

 

[moparmarks]

They will work just fine. I put 11x2.5 brakes on several disc brakes cars. Just put some on my 78 D100. My 72 SSP has them too.
Station wagons got 11" rear with disc up front.

 

[JG71B]

They will work just fine. I put 11x2.5 brakes on several disc brakes cars. Just put some on my 78 D100. My 72 SSP has them too. Station wagons got 11" rear with disc up front.

Did you use the original m.cylinder with them or is a different bore size suggested?

 

[moparmarks]

Nope I didn't change anything else.

 

[JedIEG]

I have 11s on the rear with factory discs. The 9.25 axle I swapped in already had the 11 backing plates so I went that route. I used the stock master cylinder and prop valve. Just make sure you get a rebuild kit for the right size brakes. If I remember right the wheel cylinders were a little different between 10s and 11s.

On another hand, I wish I would have swapped out the prop valve for an adjustable unit when I built the brake system because I like tweaking things. If you want to do something like that, do it now.

 

[MoparLeo]

11" brakes especially if you have front disc's do little to improve the braking on a passenger car.
70-85% of the actual braking is done with the front brakes.
You will on average replace the front brakes 1 1/2 to 2 1/2 times more often than the rear brakes.
11" on a 4 wheel drum HD application is different.

 

[JedIEG]

70-85% of the actual braking is done with the front brakes.

Yep.
I went with 11" because I didn't want to tear my rear end apart to swap backing plates to the 10". Sounds like the OP is in the same boat. I would not go out of my way to change from one to another with discs in front.

 

[gtx6970]

AAR Cudas and Challenger TA's have front disc brakes with 11" rear drum brakes as standard equipment

 

[moparmarks]

Awe, forgot about that one.

 

[mrhemi]

It is not that big a deal to pull the axles and change the backing plates is that is the reason for not wanting to undertake the task.