Welcome back Dan

You sure did put a ton of miles on that 60...I especially enjoyed when you had the old school reall buckshot mudders on it...driving the mudholes on the levee during heavy rainstorms as well as sideways thru trails in Forest Hill, etc..
As far as traveling highway speeds, etc. Your rig has to be made SAFE FIRST. Brakes top notch. Steering re-vamped. That said, the 1979 onward (all models...40's, 60's, 80's, 45's) have 3.73's.
Finally, you can't have it all (Unless you build a transformer)....an d FWIW, just enjoy the ride....take the back roads...take it easy...leave early.....enjoy the scenery...it doesn't have to be a race...BESIDES, the back roads have all the goodies AND more stops and places to get help, etc...