@Daniel. Yes, this is completely possible. When the cylinder head was removed and serviced, the block should have been too. Recommend complete the entire repair, or there is always option of just getting another motor.
Nice car, I've always liked that shape! Keep it rust free if you can.
There is a phenomenon called dieseling, which is where an engine runs without the ignition system being powered up due to auto-ignition of the fuel in a cylinder. However, this requires a mechanical ignition system, fuel pump and carburetor or mechanical fuel injection.
This can't be ...