The keyways will be about 120 degrees apart on the cam gear- - - - -I'm going to totally ignore the timing marks, and concentrate on where a line drawn from the edge of one side of the keyway intersects a tooth on the perimeter of the gear. In the mid-1970's, Datsun used the same approach on their timing sprockets to adjust for timing chain stretch. They used a dot, a triangle, and a square mark to identify different slot positions. One slot will be a few degrees advanced from the original keyway, and the other will be a few degrees retarded. Then woodruff keys with various offsets will allow me to have a much wider range of adjustment than offset keys and the original key slot would do. The same approach could also be used on the crankshaft gear. I've been setting up racing cams with a degree wheel and a dial indicator for decades, so some train driver's opinion about where a timing mark needs to be is a moot point.
Jerry
