Cadillac Repair: spark plugs, ac delco, predictable performance

Question
can I replace spark plugs with over the counter or should they be replaced with mfg plugs? The car is 1997 cad sedan deville with a 4.6 eng. i want to use bosch #4505

Answer
Hi Leonard,

        Personally I wouldn't install a Bosch plug in anything I wanted to run right because in my experience they either can cause a rough idle or running problem right from the start or with-in 4 months one or more will act up and the engine won't run correctly and have to be replaced. Just make sure to change them when the engine is warm to the touch or colder otherwise you run the risk of damaging the threads in the cylinder heads. Also it would be a good idea to put a lite coating of anti seize on the threads before installing them to ease in the removal the next time.

      What I would do if it were me is to install the AC Delco platinum sparkplugs the engine was designed for. They give good predictable performance and yes they may be alittle more expensive but you are saving money buy doing this yourself so why not install the best. Whether you buy the Delco plugs from the dealer or autoparts store the plug should be the same. Its just that the dealer price is usually higher but not always for all parts so you might want to call first.  Bill