You hit the mark with those nuts, exact match. Thing is, having found one cracked at the slot, I have no interest in using them.
There has been a lot of guessing as to why my right side duallies departed; loose lugs, tight lugs, and now I find this cracked lug after randomly selecting it to take along as a sample.
My guess as of today is that I will find more cracked nuts, and that they caused the problem, or where a significant part of it. There is no way a cracked lug nut can hold the specified torque, unless that torque is less that the energy required to open the crack.
As far as checking as to what was stock, I dont have a parts manual for the vehicle. I do have the GM shop manual covering all trucks for '63.
The side cut-away view of the hub/wheel attachment {dually and the single front} clearly shows no hub ring, and a simple flat faced lug nut. Wish I could copy the picture, but I guess it is copy protected.
Switching to a 9/16 stud would require modifying the hub and brake rotors, and probably the wheels as well.
Seems like the grade 8's I have ordered, and a drop of Locktite blue should do the trick without reinventing the wheel!
{pun intended!}
