I'm running an 07 WRX with forged pistons (wiseco), arp headstuds, TGV deletes, ported IM, and ported headers with a VF39 with Sti TMIC. Like Im_Slow said, my engine is overkill for the turbo setup. I know you have a few different pieces but whats the point of an engine capable of 500hp and a turbo that can make only 300? Dont expect any major changes, if anything you will lose some low end due to stock compression being much higher than any forged pistons out there. In my case I just havent gotten around to getting a new turbo and when I do atleast I'll have an engine thats ready to handle it.