I've read all the threads that I could find about spark plugs for the First gen 3.5L engine. From personal experience, I know that Bosch Platinum +4's are not a good match for this engine - they did, however, perform superbly in a 1984 Chrysler Laser Turbo that I previously owned. Most of the threads that I found were somewhat aged, and my takeaway was that Champion Golds were highly regarded - unfortunately, they don't seem to be available any longer. I am considering the OEM Champions or the NGK V-powers, both highly regarded by users of the forum. I was wondering, though, if anyone has used the Champion Iridium plugs in their 93 - 97 3.5's and how their experience has been.