What Size Brake Drums on 69 Chgr 440/4SP/Dana 60 with front discs

[Chatt69chgr]

What size rear brake drums were supplied from the factory on Dana 60 equipped Chargers in 1969?  10 inch X 2-1/2 or 11 inch X 2-1/2.  I'm talking about cars that had disc brakes on the front.  And are the rear drums supposed to be finned or smooth?

If the answer is 10 inch----would there be any problem going to 11 inch (and using a 7/8 inch bore wheel cylinder instead of the normal 15/16 bore normally supplied for 11 inch rear drums)---I'm asking because I already have all the parts to do a 11 inch setup.

I've done a little more reading and determined that the 10 inch drums also use the 15/16 bore wheel cylinder.  I got the idea of using a smaller bore from a article I think R. Ehrenberg wrote.  He also mentioned a 3/4 inch bore that was available.  The article said this method was better than using a adj proportioning valve in the line to the rear end.  Was just curious if anyone had done this and how did it turn out.

[gtx6970]

ft discs brakes get 10" rear drum brakes (trans am cars excluded )

Don't know about the smaller wheel cyl changes though

[BigBlockSam]

 

[mopar4don]

I am in the exact same position as the OP.

Does anyone have an answer?

[b5blue]

https://www.moparaction.com/tag/disc-o-tech/