I agree the new hydros should be able to turn them no worries but with the higher back end means more pitch to the deck to level. That means greater angle on the pulleys and belt.
Heres a pic of an 08 SZ with larger tires. I found out later the dealer didnt do a thing to the deck. Machine was for home use only so the hydro are probably ok (who knows for sure though), but can you imagine the pitch on the deck?
Wont let me upload the pic again so check out this old thread... http://www.lawnsite.com/showthread.php?t=243027