Technically, only the actual bearing hub. Some people swap rotors too but it's not necessary, the DRW rotors have a smaller stud hole than SRW so they can be drilled out. The bit size is listed in the Dana 60 Bible on Pirate4x4.
Spindles, caliper brackets, etc are all the same.
The 60 Bible also details machining DRW bearing hubs to SRW to further save money.