I haven't gotten that far yet. I had thought the holes were drilled for 7/16", maybe i'm wrong. I'd just email scarebird, although when i asked them a question they were kind of jerks and referred me to the instructions rather than answering my question. The back of the hubs are countersunk on the 5X4 pattern, hopefully when you snug down the lugs it will center the rotor on the lugs. I'll have some time this weekend, hopefully, to keep working on the install and let you know what happens.
