The spark plug gap for a 1988 Ford F-150 depends on the engine it has. Ford F-150s in 1988 came with several different engines. You
must check your owner's manual to find the correct gap for your specific engine. The manual will specify the gap in inches or millimeters.
Without knowing the engine size (e.g., 302, 351, 460, etc.), it's impossible to give you the correct information.
