11" Backing plates rubbing

I guess I must be imagining all those A-bodies with front discs, 10" rear drums, and radial tires that I fixed premature rear lockup on by swapping in smaller-bore rear wheel cylinders. Thanks for letting me know.
:lol:

Like I said, if everything is stock or relatively so you've got a point. But most of these cars aren't stock, and even with radials if you start running different size tires out back than you are up front everything changes. You have to match the brake bias and capability to the car in question, you can't just say 11" drums are pointless. On my Duster the 11x2.5" drums I run aren't enough, I could use more rear brake than I have. But I'm running 13" rotors up front, 275's up front, and 295's out back. If the OP is running 10.95" disks up front and 225/60/15 BFG T/A hockey pucks all the way around the 11" rear drums may be overkill. Regardless, that's not the cause of the problem he's having now.