Here's why:
* Engine Codes: Even within a single year and engine size, there are different engine codes (like "L05" or "TBI") which can have variations in spark plug gap recommendations.
* Manufacturer Specifications: The most accurate and reliable information comes from the engine manufacturer's specifications.
How to Find the Correct Gap:
1. Check Your Owner's Manual: The best source is your 1990 vehicle's owner's manual. It will provide specific maintenance information for your engine.
2. Consult a Repair Manual: A repair manual for your specific car model will have detailed specifications for spark plugs, including the gap.
3. Contact a Mechanic: Ask a qualified mechanic who can look up the information based on your vehicle's VIN (Vehicle Identification Number).
4. Look at the Spark Plug Package: If you're replacing your spark plugs, the package may have the recommended gap printed on it.
General Spark Plug Gap Range:
For a 1990 5.7 350 engine, a common spark plug gap range is between .035 and .045 inches. However, this is a generalization, and the exact gap should be obtained from reliable sources as mentioned above.
