I used a soft phillips head bolt that I threaded into the oil fitting I installed on top of the turbo. Then I shaped the top to fit the A/N fitting shape, then drilled it using a 1/16" bit. The 1/16" hole seems more than sufficient for that engine oiling system to provide plenty of oil.

Former owner of '99 CSVT - Silver #222/2760 356/334 wHP/TQ at 10psi on pump gas! See My Mods '05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red '06 Mazda5 Touring, 5spd,MTX, Black