I'm going to ask the local O'Reilly's if they have a heli-coil kit that I can purchase one tap from. I'm going to order two bolts from Chevs of the 40's, smallest package available...better than buying the whole set. After I drill out the hole, I believe I can screw the new bolt into the tap and screw it in without the aid of their special tools...especially since the hood hinge bolts are shouldered. Once it screws down flush, problem solved. Tell me if I'm wrong!
The helicoil tap is a special size fitted to the size of the insert. You need the whole kit, consisting of tap, insert tool and insert. The insert tool allows the insert to spring inward a bit as it's pulled into place, and then expands into the threads, like Phak1 said. If you're talking about finding a shoulder bolt with larger threads (which might be hard to do), you could just drill and tap to the correct size.
I've looked at Timeserts. They may be better than helicoil, but way more expensive. I would consider them for a more critical application than a hood hinge bolt hole (like maybe a stripped hole for an SAE boss o-ring fitting that needs a continuous shoulder for the o-ring to seat against for sealing, but those aren't used on stovebolts.)