Ordered My Disc Brake Conversion Kit

Interesting.

Still not 100% sure if they're having rotors cast that way or machining blanks for their kit, but either way they're doing a lot of work to make the 5x4" pattern work on those rotors. Kind of looks like they're having them cast that way. They added the scallops into the backside of the hub to clear the studs with the 5x4" pattern. And the outer hub is definitely being turned down or cast thinner, that outer hub/center register area is quite a bit thinner than on the stock rotors.

So the good news is the claims they're making are probably accurate, with the hub diameter being narrower they should fit a lot of the SBP wheels. And they're 7/16" too, so again they should fit most stock wheels. The track width is still changing (wider) so you'll have to pay attention to your tire to fender clearance still.

The bad news is, that hub isn't as strong as the OE hubs. That thinner outer wall that supports the outer wheel bearing isn't as strong. And those scallops into the inner part of the hub where the inner bearing rides weaken it there too. Now, from the factory those hubs are built with a substantial safety factor built in, so, it's probably ok. But hopefully someone actually did the math on that and determined the strength of that modified hub and decided it was sufficient, rather than just modifying the OE hub so it would work for their kit.