The timing isn't really as big of a help as leaning the air fuel out will be. That is where the power will be made. We just don't want to over/underadvance the engine.

It sounds like he was dynoing between 10-11 psi to me. That is pretty darn good numbers for an engine that is only 9:1 when my 10:1 engine on 10psi would spike up and then back down to 10 psi would make around 350 hp. The higher compression easily accounts for that.
So he's nearly there already at around the same boost pressure, plus his engine can be boosted even higher without too much fear.
His airflow numbers show he was making it around 27 #/min (based on maf counts which in turn is dependent on how well the maf curve is figured out) and that means he's got at least another 15 #/min available in the turbo. THat's about 50% more airflow available and I think it can fully take him over the 400 wHP mark once we get a couple of back-back dyno runs with tune corrections as well as someone who can turn a damned boost controller knob!

Wait till we get it upwards of 16-18psi.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black