I was going to suggest the 1/4-20 Allen bolt (about 1-1/4” long?) but you already thought of it.
I’ve changed a few lately, makes adjusting timing a lot easier. If only I’d thought of it 20 years ago.


•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-