I have a spare 77 F250 Voltage regulator I want to adapt to a Generator.
I have any early 1960s Generator with 3 terminals.
Field, Ground, and a Stator terminal on the back.
Can I adapt the 77 F250 regulator to the Early 60s Generator?

 

When you say Generator, do you really mean Alternator?

 

Early '60s = generator for all but more expensive vehicles.

 

Without getting pretty creative, no they are not interchangeable. The both vary the voltage to the field terminal to regulate output current, but the main battery connection for a generator goes to the regulator first, then to the generator. On an alternator, the charge current goes directly to the battery and the regulator only sees a reference voltage to verify its charging properly. If you were to use an alternator regulator, the battery connection from the generator would be connected directly to the battery, which is exactly how you turn a generator into an electric motor.