Please, people, note that three point mounting of an adjustable sprocket is the industry standard. The cheap Chiwanese"billet" copy of the Megacycle 250-00 grind mounts on only 2 points with skimpy 7 mm. fasteners that thread into a pair of thick lobes which swap place as the motor turns. A pic of the other side of that camshaft would show them. If you have some amalgam fillings in your teeth that you want to get rid of before hand to cut the dental bill, that XS Performance/Ling Ting Tong camshaft is your huckleberry. Take a long ride and it'll shake those fillings right out, guaranteed.
The hole between the slots is the giveaway. Dunc, I'm so, so very sorry. I share your pain because I got stung as well; I thought "Gee, what a price for springs and all, want that 106* lobe center!" Violated my own first rule: "You can't buy something for nothing, but you can surely buy nothing for something if it's cheap enough."
Didn't trust 2-pt. mounting on the slots, went with holes and dialed in by fiddling with deck height, upper range performance grossly impaired by them shakin' lobes, dropped motor, reinstalled Shell #1, gave Chiwanese crap to a friend who was experimenting with all kinds of stuff. He offered money and I said no, it's yours, and quoted King Edward I of England: "A man does good business when he rids himself of a turd." I'm not the only guy on the board who went there, did that, came back all pissed off and bloody and used the goddam T-shirt for a shop rag!