Setting Ign. Timing, 1974 TX500

Question about setting the timing on a 1974 TX500. The book (factory service manual on CD) says set static timing first, then set timing dynamically using a timing light. Timming is suppose to be 40 degrees advanced at 2000 rpm. The point cam plate has marks that supposedly corespond to the 40 deg. advance. But the 2000 rpm figure...is that cam rpm, not crank rpm??? The manual doesn't say. Mine needs to be rev'd to about 4000 engine rpm for the timing to hit the marks on the point cam plate. And the marks on the point cam plate (TDC & 40 deg advance) don't appear to be 40 degrees apart. ????

Thanks