You lose 0.4 inches only. These sleds ship with 1.25" track, you are going for 1", that makes 0.4-0.25 = 0.15" more clearance required than stock.
Or even better, the machine also shipped with 8 tooth drivers and 2" track -- and it came with the same protectors.
Note:
(teethx2.52)/3.14=diameter
10 has diameter 8.03
8 has diameter 6.42
6.42/2 = 3.21
3.21+2 = 5.21
So... the MRX1's that shipped with 2"x2.52 track required 5.21 inches total clearance from the center of the driveshaft.
8.03/2 = 4.015
4.015+1.0 = 5.015
So... for 10 tooth drivers with 1" track, you require 5.015 inches total clearance from the center of the driveshaft.
5.015 < 5.21, so it'll fit.
In fact, my best guess would be that you could fit a 1.25" track with 10 tooth drivers in there, since that would require only 5.265-5.21 = 0.055" more clearance than the MRX1.