Have you ever visited The Champion web page and saw what they recommend for plugs? For my '03 hemi they give you one choice, the 9403 iridium. They even make the statement that there have been no problems using nitrous oxide with these plugs.

 

I like NGK. Probably go with them when it is time to change them out. Thanks for the heads up though.

 

NAPA lists them at $9.99 ea. At that price I imagine Champion would recommend them.

 

And the 06 has 2 per cylinder

 

All 5.7 Hemi's have 16 plugs.