Hi. New to the forum and I hope this is the right place for this post. I am getting a 2021 3500 with an 8 foot bed. I'd really like to get the Mopar sliding toolbox. I can't seem to find rails for the 8' bed in the Mopar online site or any other seller's site. Am I missing something or are those rails not available for an 8 foot bed? Thank you.