21x11 would probably be about close to perfect on a 950. I almost think a 22" would be to tight on clearance after you put the tracks on. I just talked with Mike from Adair Argo and he said they do make tracks for those 11" wide tires. You'll probably be looking at paying 2 grand or more plus shipping for just the tracks without tires.
HUSTLER 980 NOS BUILD
HUSTLER 980 TRAIL MACHINE
HUSTLER 950 PARTS MACHINE [
IMG]http://i708.photobucket.com/albums/ww81/highrollinmopars/2012-06-04_07-13-01_284.jpg[/IMG]