I think we discussed this earlier, but the answer to your question is because that trailer is (1) A semi-custom trailer built to Sea Ray's specs and, as such, the goal is to keep the boat as low as possible for better trailering... (2) The trailer was built for a different boat model than yours.I've found a couple of those that might work. I was hoping to find the lower bracket though. I know they exist, cause the trailer already has 4 of them on it, they are just on the stern sides of the bunk. I don't know why they didn't use the taller ones for all 6 supports.
How much room do you have under the stern keel? Can you swap brackets around?