I've changed my plugs. I put in Bosch 4+ Platinum. They work just fine. And yes, I did notice the difference, since my old ones had oil all over them and little letters saying "GM"

) The hardest part is getting to the plugs closest to the cabin, and those on the driver's side need some stuff taken off the engine before you can get to them. But having the right tools and some patience is all that you'll need. It was my first time and it took me a bit more than an hour. Not sure about the interval, but my Cat had 100k on it. I think 60k should be the right time.
Good Luck!
