I had the dealer adjust my suspension to the bottom holes on the spring hangers before I took delivery. Mine is close enough to level and I'm happy with the clearance to the bed rails. My truck is on factory sized tires though.....
If that doesn't get you close enough, you either need a sub-frame or ditch the 35's.
2016 Jayco Eagle HT 29.5BHDS (ordered 12/30/15, delivered 3/8/16)
2015 F-350 crew cab, short bed, 6.7L PSD, Pullrite Superglide 3300 hitch