fitting 2001 Northern Lite on 2015 F350 Super Duty

We have a 2008 NL on a 2015 F350 dually and use a horse stall mat from tractor supply, then a 2” condensed foam, topped with a 1/4-3/8” rubber mat to clear the duality lights. We keep the bottom horse stall mat in when not using and store the the foam board and other mat.