Newer vehicle with electronic ignition probably 100,000 miles
A standard spark plug should last about 50K. A platinum tip plug should last 100K.
How long spark plugs last depends on the brand of spark plug and the condition of the car. In a well maintained car, some spark plugs will last from 3 to 7 years.
most spark plugs should be checked and gapped annually. if your spark plugs are used up you should replace them
spark plug gap is.044
spark plug setting should be .044
Spark plug setting should be at .31
It will be the last spark plug on the rear of the passenger side of the engine.
The spark plug gap for an AR135 spark plug on a 350 SBC should be set at .034 inches. This is equal to .86 mm so a spark plug set to .9 mm should work correctly.
A 1968 Ford Galaxie 500 with a 390 engine should use a spark plug such as an E3 brand spark plug. This plug should have a tapered seat with 18mm threads.
Spark plug gap should be .060
Too long since last change Wrong heat range for use
#7 spark plug is the last plug on the left side...that is the drivers side of the truck