so you mean, instead of using the hydraulic ram or the chain hoist, just use boat winches at the back and hook the cable to the end and make it pretty much a true crane? what do you mean by a block for a guide? using a boat winch crossed my mind, but I was unsure about the strength of the cable, and I do tend to overthink/ over engineer some things that I build..
Could I use 2 heavy duty pully's on the boom instead of a guide block. put the winch's at like 5' up the post?
something like this winch? just have to be careful not to throw it in neutral. that would be bad.. but all boat winches have neutral I think.. I wouldn't get it from this ebay seller, probably off Amazon as they have it too