The recommended spark plug gap for a 1991 Chevy S-10 depends on the engine. You need to know the specific engine (e.g., 2.5L 4-cylinder, 4.3L V6) to determine the correct gap. The owner's manual is the best source for this information.
Without knowing the engine, I can't provide a definitive answer. Checking your owner's manual will give you the manufacturer's precise recommendation.
