I have a T3 turbine housing 20358-72 with 0.63 a/r housing. The original Turbine wheel in this turbo has a small wheel, too small for the housing its in. The housing has about a 2" exducer and a 2 3/8" inducer.

The issue is that the current "standard" T3 turbine wheel for this housing is exducer: 1.802" 45.77mm and inducer: 2.324" 59.06mm.
So there is a large amount of room between the wheel and the side.


Question 1: how much room should be between the wheel and the housing.

Question 2: Looking at a T04B standard wheel (# 451311-0014) it seems to have a much closer fit with exd: 1.914" and ind: 2.322". This would leave about one millimeter on each side of the wheel. Would this be too close?

Question 3: which turbine wheel is the correct one for this housing?

I have been looking online for days trying to find the correct wheel.
Thank you very much for your time.