Yep. If your AFR is right then you need to run less timing. Each motor is different based on the cam, combustion chamber efficiency, boost, and compression ratio so you can't predict exactly how much timing a given engine will need without hands on tuning and even then you can be too aggressive. The motor will continue to pick up power even when detonating slightly so it can be misleading.
Most often the MLS gaskets will lift under boost and reseal during normal driving moreso than the old style so you end up with a little bit of a "grace period" with them but if you have bubbles you have leakage...
Also check for oil consumption. Bad valve guides or rings will cause oil to get into the chambers and oil is a guarantee for detonation.
David