I think Dave has it down pretty well. If you can't raise the kingpin/lower the hitchplate, you may have to flip the axles on the trailer to get it level again. But you definitely need to raise the rear of the truck. I would opt for the air bags (I have them now and had them on my previous truck) mainly because they give you more choice in the leveling.
Ed and Sharon
2010 Wildcat 28RKBS
2011 Ford F-250 XLT, 6.7L PSD
Ride-Rite Airbags and Airlift wireless remote compressor...nice!
I thought I was wrong once, but I was wrong!