What is the difference between these turbos? They both have a t2 exhaust manifold and the people who I bought both of them from claim that they are t25, yet the housings are not interchangeable. Please help!

 

Are they the same brand and part number? I don't think you will find too much interchangeability on different brands.

 

There is much more to a turbo than the "T25" naming scheme. Most people just say T25 when they mean T2 exhaust flange.

 

Measurements will tell you what you have. Inducer and exducer of compressor and turbine.

 

You are marking the shafts and compressor wheels before you take the turbos apart right? They are balanced. If you take them apart and put them back different you may need to rebalance them. And yeah there are all types and sizes of T2 turbos with different wheel measurements.