I'm pretty sure you can put a 200 rear tire before any swingarm and fender modifications. I ride the 1800N that came with a 180 rear tire and can fit a 200 with no problem. If you want to go with a 240 or 250 check out "sumo-x.com." They have awesome fat tire kits.
Thanks for the reply. I have been checking out those kits. I would love to have one but saving that kind of cash may take a bit. I might just settle on a 200 for now.
Brian