Yes. the 4speed. 4th is overdrive. The three speed is the venerable TH400.You mean the 4 speed? Are there multiple versions? I see 3 speeds everywhere. I think the one I’m looking at has a 3 speed th400(?).
There are two main configurations. The two man and the four man
There are three engines available. The 6.2L, the later/replacement 6.5L N/A and the newest 6.5L turbo
There are 2 different transfer cases. The early NP218 behind the 3 speed and the NP242 behind the 4 speed. Both are full time 4WD
If you are just cruising around town the three speed is more affordable and simple to maintain. It doesnt have any computer controls to flake out on you.
There are three GVWR as well 7700lb, 10000lb, and 12000lbs
The prices tend to rise with the specs. Early 7700lb two man, 6.2L ,three speed trucks being the most affordable