I have the Mirage turbo compressor and it is P/N 443705-007 and the A/R is .50.  The turbine side A/R is .58.  I also removed the restrictor in the tail pipe and fabricated new tailpipes.

Craig Berland

N7VG

My TSIO-550 turbos are Part number 646677 (std): Compressor: T04, A/R=.6 housings and Turbine M13, A/R=.58  (spec’s molded into the castings).

Curious what your Malibu’s are/say?

Rick