Well, I've used anti-sieze (nickel) on spark plug threads for over 30 years. Iron heads, aluminum heads, flat seat, tapered seat, domestic and imported, small engine and large engine. Haven't had one problem. You have to realize what the head material is and how anti-sieze affects the torque but I would think any competent mechanic should realize those two factors when installing plugs.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
