My dad called with a big block stamp number we need decoded. It is on the front pad and is the onlt number on it. It is C8B118569 Thanks

If the 118569 matches the vin it's the original block. The B if the build plant of the Car-Baltimore. 8 represent the year of the car.

you got um truck engine

C8B118569 is the con vin derivative

C - Chevrolet Truck Division (1 is Cars) of GM
8 - Model year, 68 or 78; suffix will confirm year, 3 letters = 78, 2 letters = 68
B - Baltimore Truck assembly Line
118569 - Last six digits of the VIN, serial number