can u explain why you feel a nut as a spacer is a bad idea? Just curious.
well, look at the stock front brakes. they are held on by a 14mm bolt(17mm head) into a caliper mount almost 3/4 inch thick. Toyota did it that way because under high traction, with big tires, a loaded rig, and panic stomping of the brake pedal that little 10mm bolt with the nut spacing it out away from the mount will shear off like a donut at a cop convention.