4- piston caliper "sleeving"?????

Bill,
We had our Firebird calipers rebuilt in 2005 by Muskegon Brakes:
www.muskegonbrake.com
They were super people to do business with. We shipped our calipers, they bored and inserted stainless sleeves as you are wanting to do.
They specialize in Corvette calipers. If they cannot do your KH, they may know of a place that can do them.
C