Q: No spark after head gasket replaced and timing and water pump fixed

Check all the ignition system primary circuit electrical connections to the distributor and test the coil and the distributor. Be sure all electrical connections were restored and are secure. It is possible that an electrical connector was just left disconnected, including critical ground wires, when the head was re-assembled. Basically, if there is no spark (secondary, high voltage output) that means that there is no primary circuit input. So, you have to trace the primary side of the ignition circuit to find the fault. If you would like these diagnostic steps to be performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a no start diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.