Here's the new turbo compressor housing with the aluminum threaded tap.  The stud is built up weld material and it was threaded in 7/16"X20 threads to receive a Stainless Steel Female to 1/4" barbed hose fitting.

Here's the RS2 Compressor Housing.  They used a male M10 thread with 1/4" barbed hose.  Internal threading would be very difficult.

Here's the fitting fitted to the housing.  The uncut thrust flange is welded to the top of the housing exit.  I'll cut it and drill it to fit after checking clearances with the existing thrust rod.

The original RS2 housing with fitting back in place for reference.