I have seen cams from 7 to 15 in 2* increments, and some with angled slots. I haven't seen every one mind you. 13s and 15s I think I have seen the most of.
I drilled and tapped the top of my driveshaft and threw that flipping little wire retainer away. Now I can swap cams almost as fast as someone using the FBO plate. And I have a few custom cams I brazed up.
