First of all, you should've searched before making this thread. So see below.
not many T2 flange turbos will get you to 400whp but it's been done before.
You will definitely need bigger injectors and a good tune.
http://zilvia.net/f/tech-talk/124925...-sr-motor.html
http://zilvia.net/f/tech-talk/432611...-gtx2867r.html