Unfortunately when I bought my '00 I did not research it. At the time I had a '96. Structurally shot but ran like a champ. If I could weld I would have fixed her. Anyway about 3 years ago I came across an '00 on Craigslist local to me. Went to look at it. Running but not really driveable. Impulse purchase and got her pretty cheap. So started researching fixing the issues. That is when I found out about the heads, CA Emissions, heat soak issues, misfire issues, etc. Funny thing is that as best I can tell the 0331 head is not cracked and I never have had any heat soak or misfire issues. When I got around to replacing the plugs I told myself that what ever was in there she was getting new of. Whether they were cheapo Champions or some fancy $5 a piece plug. Turned out that they were cheapo Champion RC12ECC. Which part number is now 438. I refuse to run anything else. No idea about any other plugs but figure they work for me so why mess with it. The one thing I do is every April pull and check them. Just did it. They look like they should. Might need a slight regap here and there but that is it.