yah, 6.0L cast right on the #1 cyl. 317 heads.
There was a catalyst info sticker on the black plastic cover that again identified it as a 2002 6.0.
Maybe GM used that plug style in 2002 and just picked that one for flexfuel in later vehicles??
I don't want to thread jack...
don't have info on p/n right now. blue O rings on the injectors, tho.
I tried to take a pic earlier today but my phone couldn't zoom that far in on the inj.
ENgine is at different location than me