I was thinking that when I read your post and they told me some people do it that way but it requires more math skills than multiply x 10 eh ! lol . Plus I seem to remember I actually traded 1 thick front disc for 2 of the thinner rear disc's to get the good number or maybe it was 3 for 2 I really don't remember either way it was what they recommended as any time you can get an extra disc in it is better than the thicker single disc , they send you 5 or 6 of each in the kit and I think I swapped 1 thick into the rear drum to get the number there otherwise you are swapping lock rings till you find one that is right or machining plates to get the good number .