Center register size 4.5" bolt unicast A-body rotors.

Just wanted to confirm, center register size for the unicast 4.5" bolt hubs, are they the normal mopar 2.81" or smaller? just I've measured the center of some centerlines I have and they seem to have the slightly smaller ford center 2.76" and I was planning on swapping to the later unicast discs, seeing I have the disc spindles already. Damn I don't want to bore the center out on these wheels.