how to fix overhead problems?...new heat exchange?

I have a 2004 800 RMK 151" vertical escape. Purchased used a few years ago.

I love the machine, but I am always fighting overheating problems, in all snow conditions.

Over the last two years I have added a temp gauge (to know where I am), added scratches, changed and extended the snow guard, and I am constantly riding it different ways just to keep it cool. I mostly ride trails with the family, so I realize that is part of the problem. maybe just the wrong machine, but the overheating problem is getting in the way of just riding the machine and enjoying it. others do not seem to have the same problem.

i am looking for possible solutions because I like the machine. any ideas? I had the idea of a new, larger heat exchange unit. I am not an expert at modifications but I do have a theory that a bigger heat exchange unit would catch more snow. I have LOTS of room under the tunnel for something larger than I have now. Is there such a thing as an after market larger exchange unit that would fit my problem? any other ideas?

this is my first post...thanks for any idea.