In reality, the bolt with the hole works OK. We’ve got a 273 with 300,000 miles on it and still runs better than most with 10,000 miles. Built in the 70’s with the bolt with the hole and a Direct Connection double roller timing chain. Car lived from FL to SD. And from the stories was never babied, cruised at 100 mph all day long, and has been up to 140 mph. The 273 is slated to come out this winter, but only to be replaced with either a 330 Desoto hemi or a 340. I am interested to take it apart and see just what the wear looks like after 45 years and 300,000 miles.