1. Remove the body;
2. May have to remove the running board splash apron on the left side of the chassis;
3. The engine/frame number (if still there...sometimes it is gone due to the elements) is located on the top left frame side member in the area of where the left front cowl section of the body sits, and almost directly across from the brake and clutch pedal shaft on the bell housing.
Good luck.
Pluck