So, it turns out that the troichoid will work, but you also need the shaft that drives it from the cam chain. They switched the male and female ends, so if you don't get the drive shaft, you'll have two male ends, and that just won't work. Also, you need the cam sprocket, because the drive shaft mounts into it differently.
I got this bike together and took it for a test ride. But a little ways down the street I heard a terrible sound (CraCK!), and walked the bike home and haven't touched it since. I'll have to take the engine apart (once again!), and see what that sound came from.