Doug and Tod, I've replaced the bunk boards twice on my trailer. I used untreated pine, treated pine and even used redwood once. Right now I have an untreated bunk on the port side and a treated one on the starboard, and can't tell a difference. Using the old board as a template, I drilled the new boltholes and secured them to the posts. The curve comes from the weight of the boat so there wasn't a need to put one in. There was a discussion awhile back about the proper length of the bunk boards, something to do with pressure on the hull and seating the boards on the right lapstrake, but I don't remember anything more about it. John