Hi Ken -
If you can find the casting number on the bell housing, I, or any number of the others her can tell you which bell housing you have. Since the brake and clutch pedals mount on a bracket which houses the master cylinder on these trucks, its is most likely you have the correct bell housing.
It is a very important point Barry makes, however, that the throw out bearing is definitely different on a 37 and the clutch fork is also slightly different . You need to be sure you have the right combination, and don't go back to the old carbon throw out bearing. It is trouble!
Joe
