1982 was the last year that Can-am's were built in Canada, after that production and development was outsourced to CCM of England. The 175, 250, and 400 were pretty much the same bike, except for the engine. I own the 175, it's a good handling bike, the Ohliins shocks are top notch (you'll probably have to get them rebuilt though), the Marzocchi forks are average (not quite as good as what Yamaha and Suzuki were running at that time). Bombardier referred to these bikes as 'endurocrossers' and I think they were supposed to perform both duties. If they had come out in 1980 they would have been the cats ass, but they weren't introduced until 1982 and were out-gunned by the single shock, liquid cooled japanese moto-crosser of that time. They will however, blow away any PE, IT, XR, or KDX of that era. For more info check out:
http://www.classiccanam.com
retroham, what's the year and model of your engine, I might be able to help.
I also have some parts laying around for various years of can-am.