Is it too late?
To talk you out of it?

If you must (why?) have the halyard in the cockpit. You need a mast base block, a turning block, and a rope clutch that gives the halyard a fair lead to the starboard cabin top winch.I've never understood the reasoning behind leading the main halyard aft. On my boat the sail cover does not take itself off. Nor does the halyard does not attach itself to the sail. since I have to take those two maybe three steps to the mast to deal with the sail cover and the halyard anyway, it makes sense to me to have the halyard right there too. When lowering the main, someone has to be at the mast to flake the sail. Having the halyard at the mast makes that job easy too. Same with reefing. All the clutter stays at the mast.It seems to me that leading the halyard aft makes a two person job out of what used to be an easy one person job.