Njmurvin, With your light RV pin weight, probably only a couple of inches! With a very heavy trailer pin/hitch weight you “may” get close to your needed “squat”. But, you “would not” be loved by others if you do any night driving.....your headlights would be well up into the tress. After our first trip with our Ram 3500 soft suspension towing a very high pin weight RV, resulted in night driving on low beams to replicate the unloaded truck high beams. When passing an opposing vehicle, I had to go to “high beams” to put my lights above the approaching vehicle. For our next trip.....we had air bags!
These newer trucks are ridiculously high, and make maintaining a level truck and 5th wheel RV while maintaining adequate box top rail/RV clearance, a very difficult proposition! memtb