Looks like you need more information than just the year and model on the Warn site? Like 4x4 or 2x4, and what letters follow the Rancher. Like a 06 Rancher 350 4x4 ES (if they make something like that?)
I went to Warn's web-site and found their ATV Mount number was (WARN NUMBER 68852). You need to check for yourself to make absolutely sure this is the right plate for your exact Rancher?
This bracket might fit all 2x4 and 4x4's? I'd go and double check. Just go to Warn.com to fill out all of your info. I guess they have a reason for asking all of these questions on their sire?