We made the trip in 2013 from Georgia with our fifth wheel. We had new tires on both the truck and fifth wheel and carried a spare for each. Thank goodness we didn't need them but we were happy to have them.
Our was original plan was to leave in April but we didn't want to miss the birth on a new grand child so we left about the middle of May. We took our time getting there and arrived in Canada June 2 and Skagway on Father's Day.
The only thing I would do differently is get there faster and spend more time in Alaska. The link in my signature is to my blog where I posted about our trip. At the top of the page are tabs with a list of campgrounds where we stayed and maps of our trip.
Just go and have a wonderful time! You will love it!