does the maximum spark advance field override all other spark advance fields including power enrichment mode spark advance as well as the main sa table? why does this field exist? is it some kind of safeguard against malfunction? it is my understanding that the max spark advance value does not include initial timing, but the main spark table does. correct?

 

The maximum spark advance setting is a trimmer value. Any amount of advance over that value gets cut to equal the max.

It's there to prevent the spark from firing to the wrong terminal in the dizzy....the terminals are 45* apart in a V8 dizzy, so the max. advance you can run without firing to the wrong terminals is about 40*. You can gain a little more room to work with by running more initial advance (i.e. turn the dizzy) but you'll need to adjust the tables to match.

I'm not sure if the "max spark advance" term includes initial advance or not....never really thought about it.