Actually funny enough, I DO have the NGK 5643's. Thats what I just put in the motor! Im not sure what number the ACDELCOs were, but im pretty sure they werent supposed to be used in that motor. I read long ago that copper spark plugs put less strain on the ignition system and are better at providing a spark, just dont last as long. And honestly, the most miles ive put on a car in my life was 15k and that took 2 years so I have zero problem changing spark plugs more frequently. Plus copper plugs are super affordable.

And I actually havn't planned on replacing the coil yet until I rule out the issue being the ground plate/fasteners being rusted or corroded.

And tsk tsk, talking about spark plugs in the coolant forum. I should tell your mother.

I also double check gap when I get pre gapped plugs, and conveniently one was at .60 gap and the other three were at .40. Good thing I checked.

If you're going to scold a moderator, I might just have to find an appropriate avatar for your profile.
One that reflects knowledge, sass, and more sass
You'll fit in just fine around here.

Watch our for Rube -- he's a dirty old man

Are you really a woman, or are you some dude dude dude looks like a lady?

Pregapped plugs; nothing in life ia guaranteed