KH500 Caliper Conversion
This post by Cody stone refers to KZ650 but those forks/disc are the same as KH500 (KZ650 disc is thinner).
The H1/H2 adapter will not work on KH500 because of fork lug spacing difference.

I'm using a KZ650 front end, and originally planned on using an EX500 caliper as I still have a few laying around. The thing is, I would have to re-invent the adapter bracket as nobody as far as I know has adapted the EX caliper to the KH500/KZ650 forks as the spacing is quite a bit wider than on regular H-Series fork lowers. After some more thought, I said "screw it".... I'm trying something different.

So I spent some time searching for a caliper that was a bit more "modern", and would have enough back spacing for the spokes and the correct offset (or close to it). 
After looking at brembo, aprilia calipers and one off a triumph st1100, I amazingly ended up with a caliper from a 2010 Ninja 250....   Gotta love Kawasaki as this thing is as close to "bolt-on" as possible. 

When bolting directly to the upper fork lug, it has PERFECT disc-to-center of pad spacing.

The pads contact the outer perimeter PERFECTLY, so doing Aylor's "cut out" mod will work perfectly, and all it required were making a simple spacer and 1.10" long adapter plate. This is all I had to make.

The caliper is about 30% lighter and quite a bit physically "smaller" than the EX500 caliper. Reviews of the little Ninja's brakes are good. Better than the old style Ninja 250, which....you guessed it, uses the EX500 caliper!

Oh, and if your wondering why the bleeder is at the bottom, this one is actually a rear caliper...which aside from the bleeder is exactly the same as the front on the new 250. 

Side-by-side

A little paint on the adapter bracket and spacer tube and it should virtually disappear.