Brake question

[68chrgrwife]

Hey trying to do something for hubby..are the rear drum brakes on a 8 3/4 rear end 10 inch or 11 inch?  (it is a 68 charger R/T 440)

[Shakey]

Hey trying to do something for hubby..are the rear drum brakes on a 8 3/4 rear end 10 inch or 11 inch?  (it is a 68 charger R/T 440)

If the car came from the factory with drum brakes all around - they were all 11" drums.

If the car came from the factory with discs up front, the rear drums were 10".

No go out to the garage, take one off and measure it.   

[68chrgrwife]

how do you measure it??

[Shakey]

how do you measure it??

With a tape measure.   

[Shakey]

Take the drum off and lay it on its face/front (the opposite of the way the one in the photo is sitting) and measure the diameter (across the back - from one side to the other).

If you don't want to take the drum off, get under the car and measure the backing plate.

[68chrgrwife]

how do you measure it??

With a tape measure.   

smart a$$  I meant from where to where, but you answered that...thanks..i just wan't sure....I don't usually do drums I like discs better, I can do those no problem.  Man , I guess we nee the upgrade kit soon....

[is_it_EVER_done?]

The max diameter is stamped on the outside flange surface (it can't be seen in the posted pic due to rust, but it's there somewhere). most drums are easy to read. If the max diameter is just under 11 inches, the drums are 11 inch. Just under 10 inches = 10".

Sometimes the diameter is readable through magnum 500 wheels (or some aftermarket wheels) without jacking up the car, or pulling a wheel.

[68 RT]

Charger R/T will have 11 inch brakes.

[Back N Black]

I thought all 8 3/4 rear Diff. came with 11 inch drums?

[resq302]

I thought all 8 3/4 rear Diff. came with 11 inch drums?

Not true.  If you had an R/T and got drums all the way around, your 8 3/4 would have 11" drums in the back.  But if you got the optional disc brakes up front, your rear drums would be 10".

[Back N Black]

I think i just bought a set of backing plates for no reason. well you learn something new every day!

[resq302]

You can use them.  Just need to convert all of your hardware, shoes, drums, and brake cylinder and it should fit fine.  Plus you would have a little better braking power.

[Back N Black]

Now i have two sets of 10 inch backing plates. I got a set of a guy that had a 8 3/4 rear end front disc up front non R/T vehicle? I assumed because it was a 8 3/4 rear axle that it would have 11 inch backing plates.

[Back N Black]

Sorry for jumping in on the thread BTW.