We have a member here who's RAM 2013 dually is 58.5" but what's a inch and a half between men :B My 2006 is 58" unloaded and with a little hitch adjustment I have 5.5" of clearance. It does squat a good 4" hitch up though.
Got news for you, go measure all three and let us know the results, I'm sure they are all in the same ballpark, give or take a inch and a half or so :W
2015 Tiffin Phaeton Cummins ISL, Allison 3000, 45K GCWR
10KW Onan, Magnum Pure Sine Wave Inverter
2015 GMC Canyon Toad
Previous camping rig
06 Ram 3500 CC LB Laramie 4x4 Dually 5.9 Cummins Smarty Jr 48RE Jacobs brake
06 Grand Junction 15500 GVWR 3200 pin