I assume you read the calculations in the tuning section of the megasquirt manuals? (I'd give you the link but I can't access it from work). It gives a base formula for calculating max advance and advice on setting up the table. My thought would be less advance rather than more, but I'm new to the tuning game, so hopefully somone like Ant will give you some advice based on solid experience.

If you haven't already, also try asking on the msefi forums.

Would you mind sending me your msq? I've PM'd you my email address.

Chris