Hello need some help will a ej20t engine fit on my current gearbox?

What year and model are you installing it?

 Tell us more about your car.

assuming you mean the 2004 mentioned in the title - then yes it will physically bolt up to the transmission unless there's something quite different about foreign market EJ vehicles.  in the US market anyway ever EJ/EG/EZ series vehicle since 1989 until like 2010 (and probably later) can be physically bolted up together.

 

turbos require a turbo crossmember or fabricating your current one or fabricating custom exhaust to clear the non-turbo crossmember.