OK, I guess I didn't know my presence was requested in this thread
What we did to my car was weld in a 1/4" piece of steel plate. This seemed to hold everything very well, but may have been slight overkill. I'm guessing 1/8" might be a little light so 3/16 should do great. You can just buy some 3/16 x 1 1/2" flat bar stock and cut your pieces off of it. I drilled mine and used nuts on the back side, but be fore warned that it was an extreme PITA to get the nuts on and that tapping the holes might not be a bad idea. Also, I found out that you may want to weld the plates in and then drill the holes because if the plates aren't exactly perpendicular to the bar, your holes will need to be augered out in order to make the bolts fit correctly. I hope this helps.
Rick
