Those use the metric bolt pattern though.

 

Mopar Muscle mag installed a set of disc brakes on the back of a Dart. They did a before and after test and the disc brakes stopped 11 feet shorter.

Yes the ZJ brakes have a drum parking break inside the rotor.

Considering most of the parts can be obtained from the junkyard its not an expensive upgrade.

http://www.moparmusclemagazine.com/t.../photo_12.html

 

I look forward to hearing what specific parts you use and seeing a running tab on the project. Good luck.

 

On the issue of converting 5 0n 5.5 to 5 on 4.5 wheels, it was done on my '85 Ram. The guy just swapped the front rotors and on the back he swapped the whole axle, but I would think you could just swap the axleshafts, no?

 

5.5"=139.7mm, same thing.

 

I read some where that some people were having problems using the metric wheels on the 5 on 5.5" lugs.