This is not a towing issue but hope you will help. My crew cab Lincoln LT has a 5 1/2 foot bed. I plan on making a 4 hr trip I will have 2 sheets of 8 ft plywood will need to leave the tail gate down....
Depends entirely on how the particular brand of cover you have is designed. Easy way to tell is to lower the tail gate, lock the tonneau and see if you can lift it back up without unlatching it. MOST of the latch into the sides NOT the tail gate but there could be some exceptions.