Sorry for the delayed response, but you can run the 160lb or 180lb spring. I got the 160 and had to crank it up a little bit to get the ride I wanted. A 180 would have probably suited me better at 220lbs.
I have a good revalve for those that works better with a spring change, we found that putting a stiffer spring on changes the way the skid works in the snow and requires more effort and seems to trench more