The 2 plugs i'm considering based on my research.

Stock part number is PLZTR5A13

NGK LZTR5A-13 4306

and the stock replacement is 4998.

Need a total of 16 plugs.

The 4998's are pricey for just spark plugs.

Suggestions?

Stick with the stock plugs, the topic has been beatin to death on other 6.1 based boards and the outcome is always the same. Nothing better than the stockers.

The best price i've seen is from just for jeeps. Any other suggestions?