kits available for disc brakes

MLC,

I used the SSBC kit on my '71 Dart GT that had the 10" front drums and the 5 on 4" small bolt pattern with 14 x 5 1/2" Rallye wheels.
My car also has the 8 3/4" 3.23:1 sure-grip rear end also sporting the 5 on 4" small bolt pattern with the same 14 x 5 1/2" Rallye wheels.
The SSBC kit was expensive ($830 to my door (from Mancini Racing)), but was a breeze to install. I'd use them again!
Good luck with your decision.