Most truckers mast typically have a collapsed height in the 59" - 60" range with a max lifting height of 78" - 81" and minimum or 0" of free lift which means the inner channel will raise about 3" or have an extended height of 62" - 63" when carrying load 6" off the ground. These specs are based on trucks typically in the 4000 to 6000 lift capacity range with solid press-on tires.
I have see truckers mast designed for pneumatic tire lifts (not many) but the specs are about 2" higher that stated above.
The best thing to do is contact your local dealer for the brand of lift trucks you have in you fleet to get exact info & find out what can be done - it won't be inexpensive.