[RichardJ]

Adjusting point gap will change timing. Adjusting the timing should always be done after gap/dwell is set properly.

Set the dwell on the low side of the 31-34. As the rubbing block wears, the gap diminishes and the dwell grows. If you start with a dwell of 34* , after a few hundred miles of normal wear the dwell will grow to 36-37 and you don't want that. Starting at 30-31 and you don't have to go back in there for 10k-15k miles depending on point quality.