2006 Mustang GT Premium Spark plugs and coil packs

On a car with no boost, No Nitrous, and not an overly large cam, you won't gain anything changing coil packs or changing the heat range of the plugs. But you may create problems. I have 270,000 Miles on my 06 GT (Bought new). Still have the original coils. I switched to Champion 7989 One Piece plugs at around 60,000 miles and put aver 100,000 miles on the 7989's with no problems. The ignition system is plenty strong for a somewhat stock Mustang. Changing Heat range will create idle problems without any gain. More powerful coils won't help power unless you have increased cylinder pressure from boost, nitrous, or serious engine mods. Don't overthink it. Keep it simple.