There's an active thread on 'Tuners right now about proper oil drainage for people running Holset/Garrett turbos. Thought I'd post it here for anyone who might find it useful:

Good rationale on his part. I'd opt for a bigger return line diameter if I were in that boat, also.

Saw this, and im just glad im running my own 3/4" fittings on my setup.

don't really think it matters because oil only drips out when returning and there is no oil pressure on the way back to the pan. but it does however matter if you have a .750 hole on the turbo and .125 dia on the return line because in this case it will flood the turbo. in the case of the tuners thread best thing to do is do a Counter bore like at a 45 degree on the return line to funnel the oil flow to the pan better.that would be my idea to fix that problem.