Micky vr4 has a vr4 engine in a gsr. Presume he has either a vr4 loom or a vr4 afm. They are different to the evo/gsr and magna afm. If you have the gsr afm now, then the 055 or 609 will plug straight in. Hell even the 399 evo9 afm will plug in and flow a heap more than the 609 or 055 and is round like your gsr one, and wont need a elbow. But will need a chip or ecmlink to play nice.
There is a box on the airflow comp page of ecmlink that you choose 1g afm (vr4), 2g (609, 055), or 3g (399 or any afm from evo4 to evo9)
Personally I am upgrading to a 482 afm. It is same flow capacity as the 399 at around 500hp.