You should feela little spring tension in one hole , that's the one to use. Then rotate it further CCW, should then release.
Why are you changing the cylinder? Is it because you can start it with a screwdriver? I put a new cylinder in my truck with no change in screwdriver capability. Waste of money on my truck.
with the two holes -- its the one left of the other- 12 o-clock rather than the 2 o-clock hole ,your pin will "bounce" (pin over spring) - push in then rotate left only a 1/16" then pull out
You know you got me curious , I was describing my daily '63 C10 ,so I went to my "65 and tried that and it's the same procedure
The Jalopy Journal
