I decided I shouldn't assume.... The mast of my C22 has the holes and staining for mounting brackets for the round spreaders. In the "box of stuff" I found in the boat are a pair of airfoils, but no mounting brackets. I finished modifying some brackets so they fit, then it occured to me - I have no idea if these spreaders are the right length!!! Can someone measure yours and let me know.
That's a huge "Yea!". Mine are 28 1/4. Don't know about you having metric stuff on a Chrysler American boat from the 70's. They may fight trying to be accepted as the standard (man, that battle's been going on since my jr. high years).