I have a 444cummins and it has a holset turbo on it but i cant figure out what size the turbo is. Here is all the numbers on it i could find ASSY 3525998 Serial 1668941 Type BHT4C. On the flange that goes to manifold i found this number 3526000. And on the back side these numbers were raised up 3521933 and 29 129. My brother wants to make a set of twins and possible use this turbo, but we need to know the specks on it first. Thank you for any help or advice.

 

take the cover off and measure the wheels.

A bht4c is a big turbo over 80mm