increasing the timing will increase the low end power. You decide on how much advance to give it but what type of fuel you are going to run, and what octane it is. Just remember, the more timing you give it, the easier it is for it to detonate and blow up. Most guys with pump gas motors are safe with +4. if ya go to race gas you can push it to say +7 and if ya decide to go alky, I have seen it over +11
Also remember, the more timing you give it, the more bottom end power you will have, but at the sacrifice of some top end.