I just bought an '80 Jag 340, so I've been watching eBay for vintage Jag parts. I've seen tracks on there, both new and used. You should be able to pick one up for a hundred bucks or less. If you're leary of trading on eBay, try ShadeTree http://www.shadetreesnowmobile.com they usually have a pretty good selection of parts, including vintage. Sledparts.com http://www.mfgsupply.com/Snowmobile.html has a lot of vintage stuff as well.