@uaeimran..
All EVOs use the DOHC version...
Even the DOHC 4G63 came in many versions, and setup was quite different for the Eclipse and the EVO as raerf2 said above!
Engines are same for both regions, with a little difference in drivetrain, with USA model being a lil inferior!...
Its just that the UK versions have bigger Turbos and other mods...
U can get 260/280/300/320/360 BHP Evo 9's in UK
and the EVO 8 was also offered with 405 BHP!