Vintage Mustang Forums banner

Spark plugs

342 4
I purchased this car 5 month ago and fixing it and running it, I checked the spark plugs when I first got the car and they were beatup so I put new spark plugs Autolite AR3933 racing same ones The previous owner had put. The gap was around 0.025”, I put the new ones around 0.040”, I just wanted to monitor them while I tune it. i drove the car about 300ish miles and today I took them off to gap them to 0.055” based on online and friends recommendation. See photos below. 7 of them were black on top and one had some oil on it and looked beat up for only 300 miles, now I know I could be running rich and I am working on adjusting that and timing, but does this one spark plug tell me? Anything to worry about? The car has a very aggressive cam and DUI distributor, should I change the spark plugs to another model? Appreciate any help
Hand Automotive tire Automotive design Gas Wood

Product Font Material property Eyelash Auto part

Product Font Material property Household hardware Nail
Top