The correction factors are on the rich side for 660s, and based on your excessive timing I would leave it that way. This is what I am always talking about, the AFC adjsuts AFR and timing at the same time. Its a pain in the ass. Showing the ECU 30% less air than you are really flowing moves you further down on the load maps, raising timing. I think timing is right on for what I Would expect to see with 660s and 10 psi.
The only way to get out of this rut is to raise airflow (boost). Once over 2.1 g/rev the ECU is on its highest load map and peak timing is only 16-17 degrees (this is for 2g). So if you are 30% over 2.1 g/rev, even with the 30% correction you will still get "stock" timing. So as you raise boost and airflow timing will NATURALLY drop. Most people interpret this as knock
THe trouble is the space in between. As you are raising airflow but not enough to get over 2.1 g/rev, you are stuck with high airflow AND high timing. So you may get knock "in between."
What I Would do is leave your settings where they are (they are still conservative), add in some race gas (for protection in case things go wrong) and try 20 psi and see what that gives you for both airflow and timing. If timing is high teens or low 20s, you should be able to sagely switch back to pump gas. Just log it right away to see that timing doesnt shift much.
In fact, if you can post airflow in your current state of tune that will help me determine what the ECU is trying to do.
There is a pretty good thread on all this elsewhere on the site, from about 2 weeks ago. See if that info helps as well.