how much is it safe to advance timing? Going to put plates on mine and my brothers bike tomorrow and I want to know what is a good setting and what's safe. My bike is a drag ported ss lr 392 he's got a 421 dune portedcub. We both run 112 fuel. And will be riding at sea level. I know +4 is safe but I heard of being able to do up to +7? What will give us a good noticeable amount of power and still be somewhat safe?