I have run platinum plugs on a whole bunch of different NA 5.7 vehicles 03 to 08. All ran great.

If you're under warranty, run the OE stuff so nobody will question it.

If not (or you just don't care about warranty) you won't go wrong with platinums.

A guru had spoken long ago and had told me to never use platinum plugs on 5.7s, ever. When asked "why can't I use platinums on a 2006 5.7 (which has the same coils as a 6.1, and why did the 6.1 have platinum plugs all along if platinums are so bad)?".....no answer....which at that point was a good clue to just use whatever and don't worry about it.

Am I enamoured with platinum or other exotic material plugs? heck no. For some cars they aren't worth it, and they cause alot of misfires on supercharged or other boosted applications. Then there are cars like my GTX which doesn't get enough miles put on it to wear out copper core/normal cheap plugs, so why bother with anything else.