Cut ALOT of grass this summer! If youre in CT how are you planning on riding the in the mountains? If you can make it over to Montana I will take you out for a few days and teach you everything I know (which may not be much). But I would honsetly say an upgraded sled should be your first move.
I ride a modded King Cat and it runs really well, but I have put alot more money into this thing than a newer M1000. And with ANY mod you lose reliability, and even rideability sometimes too. So looking to mod your 440Z.... not the best idea (in my opinion)
An M6,7,8 would work great; or a mountain cat 600,800 in the older chassis (which will force you to throw your weight and ride the pizz out of it and make YOU A BETTER RIDER) The price you would have to put into your sled to make it mountain worthy is alot more than a newer mountian sled. Plus the 440 engine is about half of what you need on a powder day.
The best advice I can give you is to do it now. If you want to ride out West dont wait another season, because the area restrictions are getting worse and worse.