The GT30 is an awsome turbo, highly recommend it! I am using the non-wastegated version though with a .82 housing (no lag). Garrett dont produce an internal gated GT30 this seems to be done by http://www.horsepowerinabox.com/HPIAB2/cat...ategory12_1.htm, "We are able to modify your wastegated exhaust housing to accommodate the Gt30 core in most cases, providing a great bolt on upgrade".
Luke.
p.s.
Try this link http://www.xspeed.com.au/ssport/39ecr33/ this r33gtst making 405hp at the wheels on completly stock engine using a gt30.