I will try to clarify for everyone the difference between Big Diesel Turbo's and Turbochargers that would be compatible to a street car.
What is the most common known Diesel that we can relate to?
The Cummins 5.9L of course.
The Cummins 5.9L underwent a number of revisions since its inception.
The turbocharger dimensions though stayed pretty much the same over the years....not to say they didnt change it up a little, But the Compressor Side and Exhaust Side wheels remained about the same...because the airflow requirement never changed...it remained a 5.9L throughout.
The most Common Turbocharger on the Cummins 5.9L is the HY-35.
There are H W Y- 35's the W designating "Wastegate Equipped."
HX35's
and even HX40's.
Forget the numbers in the names. The important thing about turbochargers, is Compressor Inlet (inducer) size...measured in MM.
The Exhaust outlet (Exducer) size...measured in MM.
Then...you need to know the Exhaust INLET choke size....its usually cast onto the side of the flange, or just below it...it will say something like .43, .68, .86, .98, 1.04, 1.13, or A/R, or 15cm, or 17cm or 20cm or 22cm or something.
Then, its good to know...
Whether or not the Center Section is "Water Cooled" (does it have water ports)
Or does it just have a Oil Inlet Fitting, and a Large Oil Drain hole in the Center Section.
Once you know THAT data, you can begin to try to size a turbo to an engine.
Although it is possible...to bolt a turbo from a 19L Diesel Engine onto a smaller V8, the choke size of the exhaust inlet comes into play...being that the Smaller V8 does not produce enough exhaust air to really spin the big heavy turbine wheel.
The exhaust size/flow from the V8 needs to match the Exhaust OUTLET exducer size on the turbo.
If the exhaust turbine EXDUCER matchs the adequate size of SINGLE Exhaust that WILL NOT RESTRICT THE V8, then the turbo will most likely work effectively.
Anotherwords.....if a single stalk of 3" exhaust pipe does not have a backpressure of more than 2 psi when ran on SAID engine from 1000-MAX RPM, then 3" is the correct exhaust pipe diameter size...so that engine would require a turbo with a Minimum of a 3" Turbine Exducer.
Finding a diesel turbo with the right size exhaust THAT ISNT TOO BIG and a Compressor that is also upto the task is the challenge.
I prefer to buy new, and specify all the sizes and dimensions...its hard to describe all this...but I hope I helped.