The truck isn't too high, the 5er is too low. :) I guess it's the new normal. If you flip the axles it will raise it about 5.5 inches. I also went with 16 inch LT tires for a total of 6 in. At the time I also added Dexter ezflex and wet bolts.
When you are done your rear stabilizers may not touch the ground and your 3 step fold out will need another step. You can get a step stool or build a box to step on or buy a 4 step unit. Some complain about the 4 step unit being weak. My ac unit is now 12' 10". The good part is that it's easy to get under it now and I have no problem going off road.
If you need a full 6 inches you will most likely need the flip. If you can get by with less you may be able to move the suspension if you have other holes in the mounts. Some gain lift by using the axle alignment kit. Or a combination of things. Some build a sub frame to get 3 or 4 or 5 inches. Mine was either a flip or it wasn't enough. I could have done major welding and fabrication and got by with 4.5 or 5 but for now it works. I dont really like the height but there's nothing you can do.
I even remember one guy on here saying he liked his rig a little a little higher so that when he stops and doesn't unhook, he can just drop the landing gear and raise the rig and back of the truck slightly rather than have to unhook just to drop the front of the rig.
16's put my tires close together but my chocks still fit between them.
As someone else said the truck will squat plus how much weight will the hitch and other junk add? My hitch is 300 plus generator 130 and metal enclosure, propane, gas cans, storage bins....700 to 750?