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These work just fine in my Impala SS, though I'm not technical enough to know how much of a performance or reliability improvement they represent. Installed with Taylor Cable ThunderVolt wires, using electric grease on the insulators and anti-seize on the threads.
I wasn't careful enough on installation and evidently put too much sideways pressure on the plugs while tightening. A couple of my plugs are tough to get to (transverse V8) and I wasn't careful enough and cracked the ceramic insulation on one of them. Didn't realize until I started to troubleshoot a misfire code. (P0302.) But I imagine the same care would be required for any plug.