Assuming there all cat springs, the red one would be what is stock in a EXT(a trail touring machine that is bassicaly the same as the ZR) and would engage at about 3200-3500. The yellow/green that you had in your ZR would engage at about 4500. Just make sure you use the right weights.
2010 AC SnoPro 500 - 1.75" Backcountry Track, 9t Super Sprockets, FettBro's RideTech System, J&T 4th Wheel Kit
2005 AC T660 ST Green - (Build in Progress)