I would definetdly boost that d16! Arp headstuds, new oem headgasket and the stock motor can make 220whp all day. If you wanna build it then vitara pistons, fjt rods, stock crank, stock block{no sleeves or blockgaurd} is a good reliable budget bottom end. You could use the stock head or add new valve springs, valves and a bisi 2.4 cam. People have pushed up to 600 whp throuh d16s with no sleeves or blockgaurd and vitara pistons/fj rods. I wouldnt push it that far but 400whp is easily attainable with right turbo setup and reliable. Good luck and check out turbod16.com and d-series.org for good info.