Original spark plugs 2000 4.0?

Want to order plugs for my "new" Jeep but it's not here right now and I neglected to look at the emissions sticker (have to go to DMV before I can legally drive it, it's at my friend's shop because cops will ticket you if you park it here even in your driveway)

I see tons of threads saying "use the original NGK plugs" but what part number is that? I'm searching my little fingers to nubs and am finding narfin.

thanks!

Rockauto or parts store site of your choice.. Look up your vehicle and find ngk platinum plugs

Here's a spark plug application chart and a tech tips letter pertaining to the use of NGK ZFR5N plugs.


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OK cool so NGK ZFR5N it is then? that's the one that kept coming up when I looked, but I was unable to confirm that that was what was the factory recommendation.

Just out of curiosity what is the R1? Only thing that registers in my brain is the 1963-64 high compression NA Studebaker 289, and I'm pretty sure those never came with NGK plugs, and that's not a 4.0 either