8.75 Rear End Disc Brake Conversion
even cheaper and sticking with the stock axles, bearings, and everything .....
just buying the replacement caliper (salvage yard), pads and rotors plus the 120 brackets and you are laughing.
http://www.forabodiesonly.com/mopar/showthread.php?t=128394
also alot of kits require the use of green bearings .... which as noted in a tech article from mopar action are not meant for turning corners .... just straight line acceleration.