DVPGSR is right on the money; the Mugen headgasket will RAISE your compression (which is not something you want to do when boosting an ITR....). You'll want something like an Inline Pro headgasket (lowers compression). It wouldn't hurt either to invest in some ARP Studs or even a block guard (be careful when installing this). There are also a few unworthy components in that Drag kit you should replace (aka. the crap delta wastegate with a Tial wastegate). Good luck...

Shingo

ps. If you're still set on going turbo you'll have to sell the CAI, Mugen header, and *maybe* the exhaust.