I've done a search on here and the web for a spare tire mounted carrier system for the H3 but cant find any direct bolt on system. the only thing i can find that might possibly work is a system from rotopax but its designed for jeeps. I thaught it could be adapted to work for the H3. the link is here RotopaX Mounting Bracket Solutions | Tire Mount. Anybody used this before or have a link to one designed for the H3? If it's already on this forum im sorry for not seeing it but i did a search and couldnt find it.

 

The only issue you may have with that mount is it is designed for a 5 bolt hub whereas your Hummer is a 6 bolt, but you could redrill the holes to match the Hummer pattern and it should work out fine.

 

I was thinking the same thing. my luck i would get it crooked and the mount would look like crap.