Pretty sure aftermarket XR pegs go straight on.
The early KX pegs are interchangable with most Yamaha until 1996ish (maybe needing to drill the hole out to 10mm).
My KDX has the same mounts as the older KX. I cut the foot section off a pair of Yamaha DT pegs, and then added some of GMC's peg sections too them. The Yamaha DT pegs don't flog out the holes as enthusiastically as Kawi ones do.