[WSSix]

You could definitely swap to a smaller pulley and up the boost. If the original pulley is on the blower, you're only producing 6 psi. Yes, lower compression higher boost can produce more power. However, there comes a point when the compression is low compared to power output of the engine that unless the engine is making boost, it's a turd. You're not there, but you can handle an increase in compression easily and increase boost at the same time. Add a cam and you can greatly affect dynamic compression within the engine. Admittedly, I'm biased towards higher compression lower boost engines on street cars.

Adding better flowing heads will do wonders. The issue is cost. Your stock heads are by no means poor quality heads. They can easily support more boost and a different cam. I would make other changes first. Your blower won't fit on L92 heads also.

Do you have headers and an exhaust system on this vehicle?

Without a power goal or budget in mind, you could end up running in circles. It's a great way to waste time and money. What is the intended use of the vehicle? That can help dictate what type of changes you should focus on so that you not only make great power but you make power where you need it.