I had plenty of clearance on my previous 2016 Ram SRW and the Bigfoot. On the new 2018 Ram dually the tailgate clearance is much tighter. I had to cut an inch from the width of my bed mat and my plywood. I might have 1.500" total tailgate opening clearance now. I wasn't expecting that.
But the Bigwig sway bar fits much better. It has more clearance at the tailpipe and I didn't do anything to the heat shield on the spare tire.
2018 Ram 3500 CC LB DRW 4X4 Cummins Aisin Laramie Pearl White
2018 Landmark Oshkosh
2008 Bigfoot 25C9.4
2014 NauticStar 21 ShallowBay 150HP Yamaha
2016 GoDevil 18X44 35HP Surface Drive