I would think,80-90 would be alright for maine,now maybe alaska.
And always did do just like Dave said with 4wd on tractor,despite all those people who will tell you other wise and say they leave them in all the time.
Never did do that even to a 4wd truck,still my old toyota has locking hubs,and still lock and unlock them,much more of a pain than putting a ck30 in 4wd and out.
Newer ford has the perminate hubs[or whatever you call them,]but don't leave it in 4 wheel high if not needed,you can feel it catching if on not slick surface if going real slow,around a sharp curve. Tells me something is binding a little.
And always did do just like Dave said with 4wd on tractor,despite all those people who will tell you other wise and say they leave them in all the time.
Never did do that even to a 4wd truck,still my old toyota has locking hubs,and still lock and unlock them,much more of a pain than putting a ck30 in 4wd and out.
Newer ford has the perminate hubs[or whatever you call them,]but don't leave it in 4 wheel high if not needed,you can feel it catching if on not slick surface if going real slow,around a sharp curve. Tells me something is binding a little.