Stripped frame threads

Any suggestions for repairing a stripped frame hole? I stripped out the hole where my swaybar bushings bolt into the frame, the threads are in the frame with no nuts inside or access holes to put a bolt inside. I tapped it out to the next size up but the bolt head is too big to clear the bushing mount. I was thinking of welding a nut on but I'm not sure how to get a solid weld without having the nut hang out of the frame and make the mount lopsided. I'm hesitant to cut and weld my frame as I'm a novice welder and am prone to f**ckups. I've included some pictures of the area if it helps. The car is a 1982 El Camino, stock suspension. Any ideas are appreciated, Thanks!
-Mike

<blockquote class="imgur-embed-pub" lang="en" data-id="a/PJhYRhK" data-context="false" ><a href="//imgur.com/a/PJhYRhK">Frame*</a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>

If that doesn't work here is a direct link (new to the forum, sorry) https://imgur.com/a/PJhYRhK