This shows the studs, cone washers, and locking nuts.
And here are the studs and cone washers part numbers. GM calls the cone washers "adapters".
Stud
3965137
Adapter (cone washer)
3965138
Each of these were about $3.50 a piece. So it cost me under $24 for the studs and washers per side. And GM does not sell the nuts (or at least my local dealer said they were not available). It is a 9/16-18 that's needed.
TriCounty Gear also sells the hardware separately. $20 for the 3 9/16-NF studs, 3 conical "washers" and the 3 9/16 aircraft "stover" nuts
