I have a 17' Thunderbird Seminole (cathedral hull) boat. I have been unable to determine the exact year of it. By comparing serial numbers of other Seminoles found on the internet I estimate that is a late 60's or early 70's. My question is the maximum rated HP (outboard). My ID tag states the max is 160 HP, but the others that I have checked are rated at 100 HP. Is it possible that there were different specs for this boat model?