I have a 2011 Super Z 31/60, and my friend got the new X-ONE 26/60. We were sharpening blades the other day and realized that his are only 2.5 inches wide without the cutout for the high lift fin, while mine are 3 inches wide with the cutout for the high lift. Different part numbers, but why are they different blades on the same deck? Will either blade work on either machine? We are just curious. Thanks.