dcsnomo, I am not sure if "Heavy Duty" springs are available for that model or not. I can give you the info for the OEM, Right Side is 1704-504, Left Side is 1704-505. Verify these numbers as there is also a Jag Z1 "Early Build". Check out ArcticCatPartshouse.com. You can look up most anything you need, though, I did not see any listing for a HD set. Possibly check with your local dealership, they would know better if they are available.-Mezz