First off, hello to everyone on the forum. I'm new to TC's but have been rvíng for 25yrs. I have a 2007 Lance 915 going on my 2017 reg cab F250 w/camper package and 18" rims and tires  but it hits the top of the bed rail about 1/4" before resting on the bottom of the truck bed. I have a bed mat already and just need about 1/2 to 3/4" more to clear the bed rail. I hate to add another mat because of the weight. I've been thinking of other ways such as garage floor tiles, gym mats etc. I could just put 3/4"plywood in the bed, maybe not the whole sheet, thinking about ripping it 12" for each side with some thin rubber mat adhered to it so it won't slide. Anyone run into this problem and have any ideas? Thanks