Handshifter, here's another version of the K top WL bottom motor.
It's actually a KH top end, using KHK cams. As you've discovered, the valves line up very closely. I used WR exhaust, WL intake tappet blocks. Machined my own tappet covers using the K upper covers. And yes, the K top ends just used a coating of aluminum paint on the head joint. This motor has been up and running for 15 years now, although the mileage is fairly low, not more than 15-20k or so. I didn't know about all the slight variances in tappet, cam and valve alignments when I built it, but recent inspection doesn't show any unusual wear patterns on any of the valve train components. I used the KH manifold, by the way.
you can always go to my website for more info on this bike, look for "Frankenstein", (the bike's name):http://www.freewebs.com/dicky_linn