What is a proper spark plug gap for a 350 Chevrolet with edelbrock alloy heads electronic ignition?

.045" was the usual recommendation for stock applications (non fuel injected with HEI distributo)r, if the coil is upgraded to a an aftermarket performance model then .0600" is possible. In applications where supercharging or turbocharging is used, a smaller gap is actually preferred because the greater airflow and turbulance of forced induction can disrupt the spark in plugs that have a larger gap (candle in the wind idea).