Sorry - - I missed your query - - I was busy riding a camel by a pyramid in Egypt. LOL
I have the Air Safe and love it. The ride is dramatically improved for both you and stuff in the trailer and it highly dampens chucking. I highly recommend going the 25K version to get the Holland head - - it is soooo much heftier than the normal heads, very much like the OTR truck hitch.
As for setting it up, obviously you have X amount of room between your rails and the nose of the fiver reqardless of what hitch you use. The recommended distance is no less than 6". If you are worried about the hitch going up and down 5", it does not move that far. You will normally run into problems going up into a service station or similar situations. You will be going slow - - RIGHT???? The air hitch will give the same position doing that as any other hitch. You will see the "safe" zone marking on the shock. Measure to the middle of the green zone to determine how high the hitch will sit at a certain setting on the hitch height. You will then be able to determine which hole to use in installing it. I was lucky and hit mine the first try.
2003 Dodge HO 6 speed Laramie Dually, Jordan controller, RDS fuel tank, Air Ride 25K hitch
Carriage 36' fiver, Onan 6500, Prosine 2K inverter, 3 slides, MORyde IS and Kingpin