Review on 🔥 Enhance Performance with NGK Iridium IX Spark Plugs TR55IX # 7164 by Philip Breeze

I installed them on my 1953 Chevy pickup. It has 350s from the 70s and those stubs make a big difference. I don't mean that it sounded 2% better, I mean it was VERY noticeable how much smoother it ran. I suspect that's because these plugs burn more efficiently so they get more power out of the available fuel, but whatever the reason, they're worth the money. And - Iridium is so hard I don't plan on changing spark plugs again for the rest of my trucking life, so money well spent.