u have the 10.5 housing, going to the 9 wont help much its a minimal upgrade, waste of money and time. get a bbk turbo if u want to switch turbo.

also not every dyno is the same, some read high and some read low. what you need to look at is what a bone stock 05 evo puts down on THAT same dyno.

numbers arent everything, hows it feel? take it to the track. im sure after all the mods the car definitely feels a ton better than before. how reputable is the tuner? is he familiar with evo's?

you should up the boost if its safe. and o2 housing and a downpipe will help you a lot. do the downpipe, its easy to bolt on. the o2 housing not so easy but doable.