It used to be that finding just plain K cylinders was easy, as no one wanted them. Lots of them used on race bikes to rules bore, and then sitting in the upper stories of old Harley shops all over the Northwest. There were probably 15 or 20 pairs that I looked though at Columbia Cycle in Vancouver Wa, when they used to be way out on Mill Plane Ave in a long Two story building that was likely built in the 30's. They eventually sold all that stuff off at swap meets. When I used to go in and they let me up there in the "old parts" if I would find something I wanted, I would bring it down stares the the back counter. Then one of the guys would get out an 1965 K and Sportster parts book, look up the part and charge me what it was listed for.... This was in 1988, not 1967.... New or used, I was not complaining. This before anyone really discovered K models again. There were a few around that worked on restoring them, but few and far between. I picked up every one of those cylinders and checked it for a -54 part number, as I have a KH. None to be found! Did find some other goodies though!