I'm all for the mopar action big rotor swap. Did it 30 years ago on my roadrunner. Really good bang for the buck and you won't likely do much better without spending a lot more. I still have 10 inch rear drums.

I did play with wheel cylinder size and an adjustable p valve.

IMHO, rear disc is more a race thing but, I am kicking around the Jeep rear disc swap also from Mopar Action.

Angry white pureblood male