Crane Cams adjusting nuts “Kool Nuts” 99769-16. 7/16-20 thread. I purchased these about 25 years ago for a big block Chevy that I had at the time and never used them. I forgot I even still had these until I recently moved. I did turn down the top diameter to .775 diameter on a lathe (it was approximately .810 to begin with) to clear the drippers on my valve covers. That doesn’t effect anything. I believe these are not made any longer. Please ask any questions before purchasing. Thanks !!!!