Been dealing with aluminum head engines for over 40 years now, if you do not coat the threads of the spark plugs with anti-seize, the threads of the head will come out with the spark plug. Current flows through the base of the plug to the head causing electrolysis, they don't write this in books, dissimilar metals and all this steel against aluminum.
Never was a problem with cast iron heads, sure is with aluminum. My K-D kit is about that old, 1968 as I recall, ream out the old hole, tap it and insert a steel sleeve, don't car if that corrodes solid with the head, don't ever want to remove that, Why they don't do this in the factory is beyond me, want you to have major problems as save a couple of bucks. But the only correct way to do this is to remove the head first.
Boots are boots, Model A Ford didn't have this problem, used brass strips, no boots, if left on for any period of time would bake on solid, and trying to pull them off from the top was next to impossible, like that Chinese finger puzzle, the harder you would pull the tighter it would be. Did make a tool with a U shaped hole in it where you could insert it under the boot and pull it out. But you can't do this on the Cruze, a blind hole. Not new, this concept is over 25 years old now.
Prevention is to coat the inside of the boot with dielectric grease, did this the day after I got my Cruze. Okay, the spark plug wire was replaced with a spring with a very poor plating on them, also coated that thickly with dielectric grease. Helps to retard corrosion. Also use this on battery terminals and ground points.
How about having to lay out 450 bucks for a new carburetor because a friends mechanical broke off a mixture jet, could buy these in the 60's, but not anymore. He didn't want to sue his shop, just gave me 450 bucks to buy a new one. At the rate this is going, even with a bad spark plug, will want you to replace the entire engine.
They could do all this stuff at the factory, but they don't, if you want your vehicle to last have to do it yourself. Didn't want to take my Cruze all apart, but one thing I had to do what to remove all four wheels and coat the hubs with anti-seize, aluminum wheel on cast iron. Ran across vehicles where with a flat tire, couldn't even remove the wheel the rust was so bad. How about spending a half day trying to remove a wheel bearing hub, never was a problem with tapered bearings, is a major problem now.
Want to hear a lot more? Could write a book, come to think of it, almost did with this post.
