Ted...

you can put 11 x 3 drum on the rear as long as you get the backing plates to go with them.

That is what i have on my 69 Barracuda.

I got those off a 78 Dodge Magnum or Monaco..I think...

Tony

70 AARCuda Vitamin C
71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)