i have never heard of the "t75"
have you seen it??
if it's a "T" series i think it's an older turbo. garrett is all GT now i believe.
The GT designation refers to Garrett's state-of-the-art turbocharger line. GT-series turbos use redesigned bearing systems and modern compressor/turbine aerodynamics. These new compressor and turbine wheels represent huge efficiency improvements over the old T2, T3, T3/T4, T04 products. The net result is increased durability, higher boost, and more engine power over the older T-series product line.