Spark plug AC DELCO or BERU

Believe it or not I got the Genuine AC Delco iridiums from Home Depot for $3 a plug.

Problem solved: I got a internally bad ac delco spark plug. Gap and everything was correct no cracks I could see literally just a bad plug.

Ive ran Beru ultra copper core for a couple months now and they are one step colder. I honestly dont even check gap on them and my shit runs smooth.

Use the AC Delco iridium original plugs. Many sites will only show the double platinum as a replacement but every time I've ever driven an engine with those in it, it pinged or idled rough and iridiums always fixed it.

Over the years I’ve found that the factory recommended spark plugs typically work best. There are exceptions, but my ‘95 5.7 recently got some plain Jane ACDelco plugs and it is running great.

I just put in regular AC Delco plugs and it runs great.

I recommend nothing with platinum. I've had problems with those in my 1980 gbody with a 305. I just keep it simple with old ac/delcos now. Keep it simple for less problems.

The new plug is AC Delco 41-156. Cannot tell any difference in my Gen 2 after replacing plugs. It ran fine before and did afterwards as well.

Problem solved: I got a internally bad ac delco spark plug. Gap and everything was correct no cracks I could see literally just a bad plug.

I bought eight new AC/Delco from eBay. While gapping the plugs, I noticed that in two of them, the ceramic was not concentric with the body of the plug. It's difficult to measure, but it's easy to see by eye. I'd estimate the error is about 0.02 to 0.03 inches.