Size/ Pitch

What many owners dont know about the bolts that attach the Chrysler steering gear to the K member... Nuts were welded underneath the land that the steering gear sits on. Although the gear box casting was milled flat, the welding of the nuts had distorted the land so it wasn't flat. Those bolts would work loose. The gear box would move. The welds at nuts would break. This was a problem because the nuts are not accessible.
The first solution Chryslers engineers came up with was special bolts with interference threads. You'll need a 12 point 7/16 socket for for these special bolts (special head). The second solution... Chrysler corporation provided majority of funding to develop a thread locking chemical product. Dupont got the contract and Locktite slowly became a commercial commodity.
Later on, changing how they welded the nuts in place, or what welder they used, reduced the distortion of that land. Their cost for special bolts went away. Bottom line, no matter how you repair the nuts, or what bolts you use, locktite is required.