I just got a message from Reboxx and they sent me 4 spreadsheets detailing the wheelsets they offer. Of particular interest may be the listing of axle length range sorted by manufacturer and truck type. If you want it, e-mail me your e-mail address and I'll send the messages to you. If you can't read .xls, let me know what you can read and I'll try to convert them. I know I can go to other popular spreadsheets like quatro. If you have yahoo mail, you can just view right from the browser.