Good news, I tested the latest boat lifting hardware this weekend, and it worked very well. I'll try to post photos. For enhanced stability, I decided to not attach to the trailer side guides themselves, but instead to remove the side guides and use the side guide attaching tubes on the trailer. The lift posts has a screw jack on the bottom to stabilize directly to the ground. Lift height is about 18”. I performed the lift operation by myself, and including installation of the lift jacks and raising the boat it took less than 5 minutes. The jacks lift ¼” per revolution. I just started on one side with 5 revolutions, and then went back and forth lifting by 10 revolutions, with occasional cranks on the front winch to keep the boat level. The only tool required is a ¾” wrench to tighten the pinch bolts on the trailer side guide tubes.
I’m using Bulldog Rack jacks with a rated working load of 1200#. We’re only at 50% capacity. However I should state that YOU SHOULD NOT PLACE YOURSELF UNDER THE BOAT WHILE IN THE LIFTED POSITION. In addition, I would make sure the winch strap is in new condition. It is only lifting about 200#, but ultra violet rays can degrade the condition of the Nylon webbing over time.
If I do a run of at least 6 sets, the cost will be $600. Galvanizing is extra, and the cost will depend on the volume done. Anyone interested?