Those methods work too, and I have used them on occasion myself. But nearly all of my 235 and 261 motors motors are modified so I prefer to work from a baseline because I tend to keep pretty good records for each of the motors I build to see, as precisely as I can, what each motor likes (and they all seem to like something different in timing and other adjustments). So I start with zeroing out the octane selector plate (and I don't move it from zero), getting the timing to the factory specification using the distributor clamp, and then tinker with what the motor likes from there, TDC or something more advanced. Hey couple of ways to skin a cat, lol.
