I think he might be asking about using a swivel cam cleat on the mast (new school) vs. the beam mounted cleat (old school N20) that holds the spin halyard.
Aaaa...well...carry on then. I think all of ours were on the beam and not the mast. Heck...I had a hard enough time keeping the F18 one on the mast ON the mast...ripped off three times until I pulled everything apart and mounted a backing plate behind it.
