Make sure to buy 2 Allen wrenches for them while you're there. Keep one with your tools for changing a tire and the other one somewhere safe in the cab. That way when you lose one you have a spare. Most people won't have that size, especially if they are used to work on Toyota's.
The tire shops dont like to sipe used tires because the generally have rocks in the tread. I've been able to get them to do it if was willing to pick all the rocks out and show up with the tires off the vehicle but still on the rim's. If you go to a shop that does Semi truck tires they can...
Surprised you don't need a fuel heater at those temps. I work for a fleet and when its that cold we have to go thaw out the fuel tanks before we can start them. That or change the fuel filters 3 times before they get into the shop. A lot of our trucks have a 120v heater in the fuel/water...
I'm wondering how the front axle housing and steering box faired through all the wrecks and races. Looks like they kept most of the stock suspension design for a few years