Jack Stands
I think the stands are the correct size based on my own experience with our 5'-2" draft Hunter 28.5. I use six jack stands chained in pairs for the 7,000 lb boat, which also allows me to move one at a time when we paint the bottom.Alan is right though, if you want to block the keel higher you'd need to figure extra height in the jack stands. I would think you would be OK using three or four 4"x4"s laterally under the keel if the ground is reasonably level.You do raise another question when you say you want to store the boat in your back yard. Both the keel and all three legs of all six jack stands will tend to 'sink' into the ground unless you are on pavement or densly packed gravel driveway. Our marina uses 5"x5"x1/2" plywood squares under each leg even on asphalt pavement and at least a 2"x10"under the full length of the keel. If either the keel or the jack stands are able to sink or rock, the boat will not be uniformly supported.I check our boat about two to three times in the winter to clear thje snow off the tarp and deck, check for any leaks and see if anything is settling or the chains or jackstands need adjusting.