Edited: 1/21/2008 4:23:43 PM by lucky_brew
your tire = 225/30/20
overall diameter = 25.5"overall width = 9" (based on the tire mounted on a 9" rim, so its probably a bit wider)
so with a little google-ing and searching you can probably find something. this will atleast help you decide if the optional tire is wider and the same heighth.....
ill post again if i can find something that will work more specifically
this is where i got the info:
http://www.bfgoodrichtires.com/specs/g-force-t-a-kdw/22.html