Here is a link to a three part article I wrote for TCT Magazine of my 1918 Arctic Circle trip in a 1985 FJ60. I hope for find this informative.
One thing to keep in mind, can you afford to be broke down for a week? Get a tow , wait in a hotel while waiting for parts ?
Arctic Adventures in a Vintage Land Cruiser
During the summer of 2018, my wife and I embarked on an Alaska trip. We thought we’d be gone about four weeks. 92 days, two trips to the Arctic Ocean and 13,000 miles later we made it home …badlandsexpeditions.wordpress.com
I can manage being broke down and being out of sorts for a couple of weeks. Not desirable obviously. Hence the ask on what preventative steps to take. New plugs, etc are on the list. The ferry ride knocks off a chunk of driving so that helps. I am rolling on LT KO2’s with a C rating. I run E rated Cooper ST Maxx on my 3rd Gen 4Runner which I love. My guess is the KO2 will do will enough. Not a huge fan of those tires honestly but that’s a wet and slush issue mostly.