I have never seen a bolt/nut that big on a 1/2, 3/4, or 1-ton truck. Not from the '70's, '80's, or late models (anything I've owned).
I'm not counting pinion nuts and hub nuts, etc...since you can't use a wrench on them anyways...
Generally, the largest nut on the vehicle (that the average mechanic will see) is the lug nuts. 15/16 on one of my trucks...1-1/8 on another
You're right. Pinion nuts and hub nuts are there but you need a socket to reach 'em. Ford used 1 1/8" quite a bit..........rear of radius arms on 1/2t TTB, funky exhaust manifold crossover tubes in '96, and I think the t-case lever pivot is 1 1/8" also.
Most practical use I can think of for the average Joe here is trailer balls, and that'd only be to snug them in an emergency or loosen them after broken with something else. What do 1" and 1 1/4" shanks take? I can't remember....
Last Curt 1 1/4" I snugged down called for something like 450ft lbs. I just laughed, put a cheater on it until my whole (heavy, steel) work bench began to move, and called it good. I'd bet 99.9% of tow balls on the road are under-torqued, mine included.