I have created a folder of text files re 15" wheel,
tire and gearing options, focused on the syncro, but
pertinent to the 2WD as well.

http://www.egroups.com/files/syncro-org/Text+Files/WHEELS/

You can upload any pertinent info you may wish to
share, but you have to subscribe first (very simple, no
mail option).  They require subscribing on FTP type
sites to thwart pirating of software, etc.You do not
need to subscribe to view the files.

You can access the archive via SYNCRO.ORG.  This stuff
will eventually be incorporated into a web site, with
credits to all who contribute.
steve