Honestly, it depends on what turbine wheel your TA-61 has. The PT51 turbo used the T350 turbine wheel. If your TA-61 also has the T350 wheel, then the housing should fit fine. However, I don't think it does. The next size down in turbine wheel size from the T350, is the T31 Stage 3 turbine wheel. The easiest way to tell would be to take the housings off of both and measure the inducer and exducer of each wheel. If the measurements are the same and the fin count and configuration is the same, then it's a very good chance that both wheels are the same.
Here are the measurements for the PT51s' turbine wheel.
Inducer = 2.795"
Exducer = 2.338"
Wheel Trim = 70
Hope this helps.
Patrick
