Well i finally blew the factory turbo in the fummins. So ive been looking at turbos at work. I work for a John Deere Dealership.
Here is measurements off of one tell me what u think...
the fummins has a #8 plate and 75hp DDP injectors.
Its a Garett turbo.
Compressor
6 Blades
Ind: 51.92 mm
Exd: 74.89 mm
Outlet 2.5"
Intake Side 4"

Turbiner Wheel
4" V-Band
Ind: 74.89 mm
Exd: 63.61 mm

JD# RE31258

 

Thats smaller than stock. Probably a monster from idle to 2k rpm, but after that it'll be useless. Look into something in the 62-64mm range. Make it worth your while for upgrading.

 

From the part number I found that its probably off a 7.6L (466 cubic inch) John Deere used in maybe a 55 or 60 series tractor.

What size flange in on the turbine housing? T4 or T3? Unless you have a special manifold or an adapter the cummins needs a T3 flange.