I got one of the front rotors in so I could make sure they are going to work for me.
There was a factory upgrade available on some gm half ton vehicles that used these 16.1" brembo rotors and 6 piston brembo calipers. I was able to source these replacement rotors from rock auto for $60 each.
Since they are plain rotors I set them up on the mill and added some slots for style.
The clearance in the wheel is really tight even though they are 22s. The low offset and shape of the transit wheels really only leaves 18.5" of room for caliper clearance. I need to get a caliper and verify clearance before I go any further with these brakes.