Richt, as a fellow Canadian, I can truly appreciate the woes of snow, and particularly the ineptitude of the meatballs working the counter at Sears.
A couple of thought about finding the right blower for your tractor. First suggestion would be to call Bercomac. They are located in Quebec. I don't have the number, but I am sure someone can find it. BTW, they do not have a web page yet, but I really wish they would. Knock out the middleman and call them direct. If you need to talk to someone who knows something about the blower units, call Sears during the weekday hours and ask for the manager for the Home and Garden Department. Chances are he is the one (and only) person who will have any insight.
If you want to stick with Sears, look for a clearance center as I did. I saved myself about $500 Can (that's about $1.50 US). Mine was a returned unit that looked like it never got fired up.
What I can tell you about the Bercomac blower that I got. There is a 40" unit and a 44" unit. The instruction manual is the same for the both models. I find the 44" a little heavy digging into my gravel driveway, so a 40" may have been a better choice for me. However, with 21hp, the 44" kicks a$$, and I did not have any problems. So, when you check the Sears website, and see this blower is for that tractor, and that blower is for this tractor, disregard that. The Bercomac blower is universal for 4 different sized frames, and 3 different PTO engagement systems.
BTW, I ran the unit on Saturday. We only got about 2.5 inches, so it wasn't enough to really test the unit. However, where the snow did drift up, the blower unit tore right through it.
Deere, thanks for the advice on weight. I will start my diet of Pizza and beer right away.
Sorry to be so lengthy, but I can't wait for a 10" snowfall!
BW