Regardless of what the manufacturers say....you can have 50 cans built in a run and no 2 will be the same. Same goes for rotors. I have taken 3 motors that proved themselves on the track. Baselined them on the dyno. Then checked the rotor #'s etc. And found no rhyme or reason to anything. Best motor on the dyno also happend to be the best on the track, had the worst rotor. Now the fun part, the car ran the best when I put my base dia tire on. When I started mixing rotors and cans no one combo was any better than what my baseline was.
I HAVE learned what #'s to look for when it comes to a particular track.
I really can't give anymore info publicly though. It is a closely guarded secret. (only because I keep crappy notes and have poor handwriting; typical engineer)
I do have minimum #'s for rotors though...junk is junk! And minimum dyno #'s for a particular track.
Oh, I should also mention this is all spec Novak stuff as well.