I am building a custom long bed for my 1953 chevy 3600 but I would like to use the bed strips that are already prepunched. Can some one give me the measurements of where the hole are in the prepunched strips from the front to the rear of the bed. By looking at pictures I think there are seven holes, maybe? I need this information to determine where to put my cross members. This is a long bed that I am building.