[b-man]

The original design was terrible, tapping threads in a relatively thin frame rail was a half baked way to do the sway bar attachment. As many of you have found the first time you try to replace the bushings or upgrade to a bigger sway bar the threads in the frame fail. Of course going to a larger stiffer sway bar increases the the stress and the ability of the one or maybe one and a half threads at best that are tapped in the frame to hold.

When I upgraded both of my ‘64 A-body Pontiacs to the 1-1/4” T/A front sway bar I had the front bumper removed which allowed fairly easy access to the inside of the frame. I was able to place some 17mm hex M10 metric nuts inside the frame and used the factory metric sway bar bolts. Nice and tight installation, those large hex nuts provide plenty of area inside to prevent any kind of pull through and are likely stronger than a Riv-Nut.

The frame rails are pretty straight in front so probably much easier to get those nuts inside on ‘64 - ‘67 A-body cars than on later ones.