jebers,
I have seen hitch mounted tire carriers. I added a hitch mount to the ranchhand grill guard on my F250. I use it for a rack that can carry a cooler or firewood as necessary (around camp). The hitch mount is a "universal" style that I bought off craigslist - the universal models allow you to adjust the width between 2 points. I drilled each side of the grill guard upright to accept the hitch. Doing that in conjunction with a hitch mounted tire carrier would achieve what you want plus allows the flexibility to easily remove the setup as desired. As others have stated, ensure your are not overloading any of the items in the setup. You might even consider chaining the tire to a solid point on the truck with enough tension to keep vibration down to a minimum - the "chain" could even be a cable with lock.......and even keep the length such that if you did have a catastrophic failure, your tire would not turn into a 70mph speed bump. Following is a pic of my hitch mounted to the grill guard.
The rack I use is an atv sized rack and for lighweight hauling only around camp.......I keep total weight down to 50lbs or less. Your tire/wheel combo will probably weigh more. The front hitch has also been useful for manuevering trailers in tight spaces.
Following is pic with rack up (forgive my shop mess - it was under construction at this time).
With rack down: Note - in this pic, you can see the 2 bolts used on the driver's side upright. These are the holes I drilled (2 each side) to mount the hitch. The hardware is grade 8 btw.
link for a hitch mounted tire carrier or you can easily make one to your own specs:
http://www.etrailer.com/Trailer-Car...tml?feed=npn&gclid=CLClibzG5K8CFU6MtgodBHzI_A