My engine code is AUM and it is fitted with the ko3s at the factory. It is only a 150bhp model tho.
Then add Revo, a ram air filter and a 4 bar

Take it to the rolling road
220bhp - 247lb tourqe
Happy days all round.

A lot of people recon that it ain't worth getting a KO4 on the golf if you got a KO3's as the difference is minimal

Oh yeah, the AUM is VVT too, even tho its only 150 as standard