Cam Degreeing

[TwinKam]

Its understandable to want to get it as close as possible but don't lose sight of the fact that most production engines of that era are only as close as +/- the nearest tooth... and as soon as the motor has any hours on it, the chain is stretching and the sprockets are wearing etc.
A lot of modern engines now have no key or dowel location on any of the timing sprockets; each shaft is held in its optimum position and then the sprockets bolts are tightened. The timing is thus infinitely adjustable.

[Belle427]

Some cams are ground with 4 degrees of advance built in which makes sense.
I’ve read that even the cloyes true roller chain I’m using will still stretch a certain amount.