DW,
I had the same question when I picked up my '09 3210. Back then the axles were rated at 5,200 ea for a total of 15,600 lbs plus the max pin weight of 2,400 for a total of 18,000 lbs.
Sometime after I ordered and it arrived, the axles were changed to 6,000 pounders. 6,000 x 3 axles = 18,000 + 2,400 Max pin weight NOW = 20,400 lbs.
The factory confirmed (with Lippert) that the hitch sticker you see has to do with Canadian certification ratings. The hitch is rated for more than the 18,000 lbs on the Lippert sticker. Here is a posting from the then Heartland Presidente, Scott Tuttle, regarding the hitches on the BigHorns: (Link)
From what I have read on this Forum, CA law enforcement will look for the GVW rating printed on your Cyclone's VIN sticker.
Hope this helps some...
