I used a piece of square tube that a hitch fits in and drilled holes for a pin , looked at the winch and cut a square hole that wouldn't interfere with anything and welded it I haven't made one for the 4001 or the hydro one yet but I will . I built the trailer a few years ago to be hauled behind an atv but it's seen plenty of tractor duty . A few of the details are here on the trailer . Better pic of the hitch .
And yes , I have a self opening block plus several regular one of varying sizes , 1 of the T-1 fitter from Hudson and 1 from a local Krpan winch dealer .