Spark plug NGK or Motorcraft

I’m now running factory heat range NGK 94833 plugs gapped at 0.03 and the car runs so much cleaner.

I don't understand why you didn't just get the NGK iridium plugs.

I've ventured from NGKs and always go running back.

I did reduce the gap of the PFR7Bs to 0.025" when I was running DriverMotorsports K04+ tune and it boosted more than 26 psi. I did so due to upper rev stumbling, but for being back to running my GIAC HO K04 tune...0.028" works. PFR7B usually work great with higher boost from turbos and tunes when you do notice the stumbling for having arc disturbance.

It appears you already have a good set of coils, start with plugs, buy good ngk plugs. These engines eat plugs especially once you start throwing boost at them, I’m running one heat range colder than factory in mine right now after smoking a factory spec set but I’m pushing 20psi so your results may vary.

Running the ruthenium plugs. Works good for me FR6AHX-S (94279)

Definitely get NGK’s - the parts store I went with initially gave me other plugs and even with a new DIC the engine was still misfiring without NGK’s

NGK is prob the best sparkplug for performance, Denzo is a cheaper option but there not as good for performance

I changed spark plugs to NGK laser platinum plugs with a 0.32 gap. The issue only arouse after I got the tune.

Most imports (To the US) don't like anything but NGK/Denso.