The hx52 is not a t4. It is a hair bigger, a carbide bit can make a t4 flange fit. The hx52 pro maybe a t4?
i have 2 of them and they are both 58mm. If people really want to, i will got take a pic with the caliper on one. The only thing smaller on the he341 and hy35 is the Compressor wheel.
Garrett
GT55
Turbine Wheel
102/111.5
Comp Wheel
84/123
89/118.5---145lbs/min
91/133-----153lbs/min
94/133-----160lbs/min
106/141----185lbs/min
Housings
T6 1.0, 1.18
GT60
Turbine Wheel
118/129.5
Comp Wheel
106/141-----185lbs/min
Housings
T6 1.25