here are the rings I made that replaces the spacers that are used to bolt the caliper bracket to the axle flange. the bracket bolts directly to the flange, these ring spacer go between hub and rotor. I will press the ring to the hub using stock studs then the rotor bolts to the ring using 8 5/8 18 grade 8 bolts and crimp nuts on back side of ring between the hub recesses. you can see the shoulder that locates the rotor on center so everything is concentric. clearence from ring to hub is .005, and from ring to rotor is .005. i figured thats plenty close enough. they look like wheel spacers but they are not. they are part of a disc conversion set up.