Harbor Freight 500lb. cargo carrier for a spare tire?

This is a pintle tow hitch mount, and has 8 holes in it for $40.

http://www.etrailer.com/Ball-Mounts/MaxxTow/MT70038.html

This combined with a front hitch might solve your problem to carry a mounted tire on the front of a vehicle. You might need to have another flat plate of steel or aluminum bolted onto this thing to support some of the 8 lug nuts. You can carry a 16" rim with only 2 bolts, but I would recommend 3. At 6,000 pounds, it can certainly carry the weight. . .

Have fun in Alaska!

Fred.