Review on 🔌 ACDelco Gold 5 RAPIDFIRE Spark Plug (1-Pack) by Lance Alvarez

Installs in TPI after removing old spark plugs. These plugs must be closed prior to installation; 6/8 of me were badly wrong. Also, remember to install them on a completely cold engine and use an anti-seize compound, especially if installing them in aluminum heads. They led to faster starts and noticeably smoother idling. I can't say for sure that they increased performance because I changed so many things at once, but I don't see how they could hurt anything either. I was concerned that the threaded portion of the candle is much longer than the stock candle and therefore the candle goes much deeper into the combustion chamber. I called ACD and they assured me they fit and work properly. This is what most of the TPI people recommend and they seem to work as advertised.