Added a Scan Gauge II to my F-150 5.4L a couple of months ago and cannot believe how happy I am with it (wish I had done it a long time ago). Check their website and/or give them a call but if your rig is 1996 or newer it should have the standard OBD (on board data), port that the SC plugs into. I had to call their customer service to get the codes for the transmission fluid temperature display but programming your unit is very straightforward and they were helpful and easy to work with.
Most of the newer trucks, RV's etc have data displays but don 't give you 4 separate displays at once like Scan Gauge does. I usually run with coolant temp, trans fluid temp, average mpg and real time mpg but it is only a keystroke or two to change to any of the dozens of other displays available. I can't imagine ever running a Class A or C much less towing anything without one. It will be the best $150 you ever spent.
I have one of These Scanguage II s in my 2002 Southwind on the F53 Chassis. Works great! It does have to be programmed for tranny temp, but not too hard to do. (Here's the instructions to do that on the F53)
2002 Southwind 37U Ford F53 - V10
2007 Jeep Liberty Toad