For anyone intersted in the disc brake conversion and/or a 9 plus rearend, here are some companys to contact...
Currie Enterprises-
They specialize in making "better" 9 plus rearends. If you have some cash to throw down on a new rear, here is good place to look for one.
http://www.currieenterprises.com (714) 528-6957
MFG Truck Parts-
You can get a really good Disc brake conversion kit for older trucks. In most cases you can get a kit for your truck that will keep you from having to modify ball joints and parts to fit the spindals. The kits are also complete and they are around 300 dollars or so.
http://www.mfgtruckparts.com (949) 279-0608