Hey mate
I'm pulling 281kw with 3076r and still have the standard box and no chassis modification.
I don't launch the car or slam gears so the box has been fine for me.
I got Walbro 255pump on special at Shift Performance 255L I think JDM yard has a special on them at the moment
I'm getting a plenum and throttle body upgrade soon and with same boost should hit 300, only 18psi
I don't redline it everyday, race, or slam gears everyday so I think I should be OK lol
Powertune has a couple over 300kw too