Some notes:
Carbo blocks are nice but I have cracked a few after years for sun exposure and impacts. I use the traditional 57 mm with the steel strap.
see Rick’s picture and ensure you buy a long enough track to handle the No2 jib leads which tune forward.
When you go to place the tracks, measure from the bow to the first hole to ensure the leads are the same on both sides. Before placing the tracks, drill and extract one or two pin holder holes between the factory holes for better adjustment/tuning.
On the cabin top tracks, there are Blade and Working Jib tracks. Which are you asking about?
In windy chop, the blade will not punch through the waves. We have sailed the No2 in 30kts and it is the way to go, in my opinion.
Bill Murphey
Chowder, #176
Fleet Captain
Fleet 63, Barnegat Bay, NJ