V8StickConv

Thanks BGnAR. That's basically what I did too. No misfire codes of any kind thus far. Engine is still running smoother than with my 10 year old SP514s. I wonder if the MSD is supposed to make a hotter spark with iridium that compensates for the smaller than factory gap.

Goldenpony

The only benefit of iridium is longer life. Not a hotter spark.

V8StickConv

Ironically, I've read that these MSD spark plugs are rated for 50000 miles, although the MSD warranty is only one year. By contrast, I have read that the Motorcraft SP platinum spark plugs are rated at 100000 miles.

Maybe it's longer life in racing applications. At least I can say the MSD are good performers so far and I won't have to worry about them breaking in 2 whenever I remove them. As to longevity, I'll have to try to remember to report back after 2-3 years of use.

tbear853

I bought the Lisle tool a few months ago as I ran across a good deal on it and I have a '07 FX4 with 5.4 and the '08 GT ..... but the '07 only has 52K miles now and the GT has but 28K so ..... maybe I do the truck this year and the GT ....... "later".

Color me subbed.

Goldenpony

I've got over 100K miles on the Champions. Good performers and no worries about removal.

V8StickConv

Glad to hear an endorsement on the 1-piece Champions. I read several posts knocking them, surprising given cost.

V8StickConv

Update on the MSD spark plugs at .035". After running with that gap for 2 weeks, I experienced a loss of overall power and 3 shut-offs as I was coming to a stop. I widened the gap to .043", which is the max gap the MSD spark plugs will tolerate, at least according to MSD. So far the car is running better with the wider gap. Also, no shut downs. .043 is close to the factory gap of .045, although there seems to be some debate about whether the factory gap is wider that .045".