tdo4 question- restrictor?

[mavx]

i have my wrx tdo4, i can see a small hole in the oil feed on the center section, is that the oil restrictor or do i need to run another one for my n/a-turbo?

ive turboed hondas and vw's using t3's which ive always had to use a restrictor, but ive never used a tdo4.

anyone who knows a thread size for the oil feed would be a plus too!