Iridium spark plugs anyone use

[Factory Guy]

I run the factory plugs and electronic ignition in both of my old GM vehicles. No issues. I wouldn’t waste my money on iridium plugs unless your vehicle was built for them. Most automotive manufacturers who offer these iridium plugs advertise 120,000 miles for a set without changing them, however that being said they are in either all aluminum engine or at least an engine with aluminum heads. Our old cast iron heads and blocks probably operate at a different temps (in the head) than the newer engines.

For years i ran standard denso spark plugs in the truck, because i could get then easily and very inexpensively.

Today i now only run AC delcos. No fouling or miss firing. I haven’t pulled a spark-plug in the Chevelle in probably 7 or 8 years. Truck is probably the same.