Chris, when you stop and consider the fact that your style of axle not only has to support the weight of the vehicle but it does double duty and supplies a path for all that torque to get to the ground, it needs all the help that it can get. Most santioning groups require (and rightly so) that after certain power levels are achieved that the bearing retainer plates be up dated too. A 9" has non floating axles and there's a chance that they can break, and you want all the engineering you can buy to keep that thing attached to the housing so you can get it stopped.
As far as the caliper goes......NEVER, NEVER try to modify the engineering that has gone into a braking system. A braking system has to deal with thousands of pounds of stresses in a lot of different directions and......well, you made a good decision to change the modified pieces.
Rob Hawes-Anchorage Rod Works-Anchorage, Alaska