Kelsey Hayes longer wheel studs
Greg
Thanks for looking into this. I never needed to meet that rule but do find the standard studs are a pain when swapping on wheels with shouldered lug nuts (like old style cast slots). Since I do this every autocross, long studs would be a time saver. For the rear on my car, I had some long GM style 7/16 studs ground down and reknurled.
In post #7 you mention possibility of metric thread but the link you posted is to a 7/16 threaded strud. I think it will be the same as US when you get it. Even in the 1980s we found Ford Australia had slipped in a standard size bolt - drove us nuts for a while because it was called out as an M something on the drawing.
The example in the NHRA rule follows your logic the important factor for a good thread engagment is to be 7/16 deep on a 7/16" diameter. But the question remains how your local track inspector will interpret it.
Matt