Well, to be honest, seems to me with your current 3.42 axle ration it could be a struggle on hills. I wish the axle ratio was lower on mine when in hilly area.
But maybe some with a GMC or Chevy will chime in.
2012 Fun Finder XT 276 Toy Hauler & Harley Davidson Ultra Classic with Condor wheel chock
2014 Dodge Ram 2500 AT 4X4 Crew Cab 6.4 L Hemi, 373 gears, tow package, Rambox option, Revolver X2 tonneau cover, Equal-I-zer anti-sway hitch.