<--6'5"
My '96 SR5 had no moonroof and manual cloth seats: never had an issue with head room. The seat was pretty low and not "thick" padding. Sometimes back would get tight after 4+ hr drives because the seat was kinda thin.
My current '99 Limited has a moonroof and auto leather seats. The roof line is maybe 1-1.5" lower. The seat seems to sit up higher (maybe to make room for the motor) and the base seems thicker, but not by much.
I will say that the moonroof does inhibit me from a true upright, perfect posture pose (although I also suspect my torso is a tad long). If I exaggerate sitting up straight, my hair will touch the roof glass and my eyesight line is near the top of the windshield. But with the seat lowered all the way, and pushed all the way back with a slight decline, I can drive comfortably enough, and have yet to smack my head on anything unless I am deliberate.
While 3rd Gens will never have the headroom of say, a 1st gen xB (driving one of those feels great), I think you can drive one in comfort. For what it's worth, having sat in 4th and 5th Gens a lot, I felt like the 4th Gens were about the same but the 5th seemed even shorter, like it only got bigger on the outside.
Still thinking about one day replacing my front seats and getting lower brackets (a seat with a longer back mostly) and figuring out how to do a moonroof delete. I never use it and would prefer the headroom gain. I'd go through all of the trouble to do these things rather than buy another car with more factory headroom because 4Runners (esp 3rd Gen) are just worth it!:nod: