I'm pretty sure there's no thread on this subject so I won't bother scrolling through all of the threads looking for an answer. Doe's anyone here happen to know the thread size for the 66-68 8 lug rim lugs (or lug nuts) ? I think they are 1/2 but not sure. Also, can you use 32 of one king of lug or do you need to buy the set specifically made for 8 lug rims with the reverse thread for one side. Or did GM only do that for the 59-65 8 lug rims. The reason I'm asking is that the set costs $179, but the single lug nuts are $1.15 each A big difference and I hate to find out afterwards that I spent way too much for something. Any help would be greatly appreciated. Bud

Hi Bud, welcome to FP.

The original Kelsey-Hayes 8-lug wheels did have LH and RH threads through out the entire production run. The thread size is 1/2 - 20. So if you are staying truly original you would have to buy the dual threaded lug nuts.

That said, you could replace the reverse thread side of the car with new standard wheel studs and buy all the same lugs. However, this option will require some work getting the old studs off the wheel hubs, front and rear.  I Doubt a concurs judge would ever know the difference.

Edited February 2, 20178 yr by Frosty