Review on NGK Iridium IX DCPR7EIX Spark Plugs: Harley Davidson Twin Cam (Pair) - 1999-2016 Model Years by Robert Pierce

So I randomly chose .032 as Harley claims, Low - Road King, test drive. The bike was sharp, like a wobbly bike, but obviously with the wrong spacing. I wanted to go back but changed to .040 inch, not metric btw. And now it works like a factory. Everything seems fine, no real improvements but it's fine so I'd say it's a good OEM replacement but I'll just buy a branded Harley next time. And yes, I think they were distributed correctly out of the box. I messed it up by pinching the bottom end of the Harley lineup.