If you remember, my turbo oil drain goes directly into a hole in the side of the head that had a large plug from the factory. Of course they could not use something with a common thread size, they just had to come up with some oddball size that you cannot find hardware for. It is a 3/4 inch thread but the threadcount is very fine. So what I did originally is just stick the hose in the hole(it fit tightly). I know this is not very scientific, but it never leaked a drop. The real issue was that the hose was not made for oil and I knew that I would have to deal with it sooner or later. Well...the hose got really soft, so I decided to fix it more permanently.
I used a 3/4 garden hose adapter as seen in the pic below. I added a large o-ring that fits perfectly inside the smooth part of the hole before the threads.
I added a good amount of RTV to the threads and cross-threaded that sucker in. It is very tight and is not going anywhere!
Here is a pic of the oil drain on the bottom of the turbo.
I used an oil rated hose(same as I use on my oil cooler). There is no clamp on the adapter side because the hose is so tight that I could barely get it on to begin with.
Finished....no leaks and no oil drain issues!