I also use Harken 1988 mast base blocks but only for the centerline and starboard wing halyards. Main halyard leads below deck and is cleated off there; the port wing (primary spinnaker halyard) is jointly cleated on the mast and a Harken 57mm block w/ cam cleat.
To redirect the two halyards aft, I use Colligo static line guides. No need to use a block or Schaefer/Spinlock style line guide. Starboard wing exits the mast to port and goes to a clutch to the left of the companionway; centerline exits to starboard and goes to a clutch to the right of the companionway. Both clutches are backed up with cam cleats mounted on the aft face of the cabin.
Jonathan