Essentially, Drew answered your question and he has given you mostly correct information. To expand a bit further, the 80 was initially designed for the 200 series but if you add the optional "wings" to the sides of it, the cutting width will be increased from 38" to 42" and that allows it to be used on the wider 400 series tractors.
The 84 blower will fit both series of tractors but it is not recommended for use on 10 and 12 hp models by Case in their Planning Guides. All the same, owners of 210's, 220's and 222's have stated they use the 48" wide blower quite successfully by not pushing it too hard. The type of snow being cleared plays a huge part in how well the larger blower performs on the smaller hp tractors.
Gee Castoff, I just bought my R80 snowblower last night from Matt over at the yahoo page, having it shipped next week, and had spent about two hours prior to seeing the question here studying the parts list on the ingersoll website. I got my info directly from the application chart in the manual, how am I "mostly" correct? Not trying to start a debate, just wondering what part wasn't correct?
edit, nevermind... WE both went a bit far volunteering info since the OP only asked about a 222, so the answer only really applies there. No big deal.