Moat likely turbo oil-feed off the left side of the head.

It's possible, but he hasn't said if he's got a 1G or 2G, since only 1Gs come with head feed from the factory. Could also be a clutch slave cylinder banjo bolt. Actually those are the only two places I can think of at all, that use this type of banjolina.

Fuel filter uses this type of bolt for 1G’s I think.

Turbo water inlet/outlet on some turbo's, oil in on some turbo's.

Are there any markings on the head of the bolt?

Oil feed

Thanks for all the replies.
2g bottom end, 1g head. Is what I was told when I bought it. Still learning how to tell the difference. Only mark a 7 on the top of the head. I thought oil feed but it's not dirty with oil. Not a water cooled turbo. Have to get back under the car and look more.
Hope to have running in a couple months.
Got lots of stuff to check. Been sitting in storage for 7 years.
Turbo rebuilt, new water pipe, has a micro tech ecu. Needs some help to make current.
Tony