My guess is by the start of next winter there will be diferent belts/pulleys to regear, i will also bet with the belt drive it will be easier to do a 3" since all you need will be a new base plate for the belt drive and maybe a longer belt....and..as of right now..no one makes a 1200 belt drive kit for the pro..so to upgrade you will need the jackshaft, mnt. plate, pulleys,belt,rotor and bolts from the 13 setup, I have been told the driveshaft will work but the 13 uses an aluminum driveshaft(more weight loss)....it is glued in(same as the 12 chaincases) but that really isnt that big of a deal....