Swapping to 5 on 4.5 pattern with Swap Meet/Junkyard parts?

Newbie here, pardon the question repeat if so....search failed me. Have been doing this sort of thing on Fords for years, but this is my first Mopar, hoping for something easy....

I would like to change over to the 5 on 4.5" wheel pattern on a 71 Demon. (Saw it on a local 72 Duster and liked it....) Also a friend gave me a very nice set of later model 5 slot rims with track tires, which I found do not fit so well on the A-body small lug pattern.............and I'd like to run them.....without buying new wheels. (I can then swap them between "other" cars also!)

SO, what is the hot ticket for swapping on rotors with the larger bolt pattern??? I'm presuming K-H supplied brakes.....so calipers could potentially be the same, spindle spacing, maybe...hoping so.... and wondering if swapping on a set of the larger pattern 73-74ish rotors is as simple as dropping the caliper, pulling cotter pin and yanking old off, push new on...and reinstall caliper?

Same goes out back. Is there a factory axle(s), again perhaps the 73-74 A-body parts or some B-body parts that slip right in with little fuss??? Or are we talking a forklift swap, or totally custom axles??? (ie redrilled)

Thanks in advance!
Steve