Haven't had much time to work on the C8 lately, but slight progress has been made.
Although the original lug nuts ran down the 5/8-18 threads on the new adapter studs OK, they seemed slightly loose. I assume the originals are BSW thread?
I didn't have enough lug nuts for all four new adapters anyway, so had these cone washers made up using an original lug nut base as a pattern. Sourced new nuts to go with them from McMaster-Carr that, together with the washers, look close to original lug nuts I think.
So now I finally have the tires, wheels and completed adapters to put on the C8, but with my current seven-days-a-week work schedule, I can't find the free time to install them!
Thanks, David