I have a pacific trailer galv with a toung extension. When sighting by eye down the hull from the stern a could see a noticeable indentation of the hull at the forward end of the bunk. The keel is sitting hard on the center keel bunk. After looking into the problem I found the forward adjustable bunk supports were bottomed out and could not go any lower. So I removed them and cut them down so they don't bottom out on the U bolt the indentations are gone. The front bunks on my pacific were to high and needed fabrication to fit my M 17 hull. If your not sure about your 17 I would take a look from the stern and sight down through there and look for a dent in the hull. There was a lot of stress on my hull from a ill fitted trailer. I only cut off 5/8" and that was plenty for my problem. Sent from my iPod