I took my 05 600 HO Renegade out west last year. I changed my jetting and gearing. I don't remember what jets I used, I still have them somewhere. I called Mavericks in Laramie, WY and told them what sled I had and where I would be riding and they told me what jets to put in. As for the gearing, I dropped 2 teeth (I think) but didn't think it was necessary. When I changed my gearing, my top end dropped to 60mph, I had to change my clickers on my clutch bc I was over-revving, and I was the only one to run out of gas.....TWICE. That was even with riding with some M-1000's. Therefore, I wouldn't recommend regearing, 1) it's kind of expensive, 2) you don't really need the extra tourqe, you will be limited by the sled itself in deep pow vs. worrying about climbing the steep, 3) you will burn through way more gas/oil.
I hope that helps, if you want additional information, I can help. If it's your first time, you will learn a lot from the "seasoned" riders. In the open stuff, as long as you got momentum, you should be fine, but the deep and steep you will suffer without a long track. I loved it so much last year that I just finished the final touches on my new Summit for my trip in 2 weeks. Kept the gade for trail riding, and set up a mountain sled for the "premium" riding. Have fun and be safe.
