104 Sunoco advance timing IGL/IGT over 93
 

Well my three bar is on. Set a published offset in the datalogit. (not calibrated to verify, its close) I have the boost timing @ 15 on 15 psi with 14 @ 17psi up to 20 with a split of 12.
I was wondering how much advance I can change my 93 base map lower boost IGL up to the 15 psi.
I read one to two degree advanced across my IGL /IGT maps because of the higher octane Sunoco.
My knock is down and high 10's AFR from 16-20 PSI but below 15psi the car sounds smooth but lost a little something. (need advance?)
Are the 9's(plugs) all the way around too hot a plug also? This is for daily use and some track.
Thanks