

-Sapo


Yep, they're crimped at the factory. In the old days when tanks and cores were both brass, it was common for radiator shops to rebuild or re-solder them as separate entities. Nowadays the assemblies are basically non-serviceable throw aways.
You want performance, or longevity? NGK's have harder electrodes and last longer, but they foul easier. Densos are softer and thin out quicker, but they produce measurably more powerful discharges. I've been using both interchangeably for years in everything from my mother-in-law's Taurus to my Kawi Vulcan and never had a lick of problems with either one. If they're a PITA to access then I use NGK for the long wear, if they're not then I go Denso for the better spark. Iridium is iridium, it's an element on the periodic table which is (ahem) public domain last time I looked. Everybody uses it, it's the underlying construction that differs from brand to brand.



