The spark plug gap for a 1977 Chevy Nova V8 isn't a single number. It depends on the specific engine and ignition system. The gap should be specified in your owner's manual.
However, a common range for a 1977 Nova V8 is between 0.035" and 0.045". This is a general guideline. Always refer to your owner's manual for the exact specification. Using the wrong gap can lead to poor performance, misfires, and engine damage.