i just went to my local auto store and asked for sparkplugs for my L and they gave me autolite double platinum plugs #APP103, is this a good plug to be running on a stock lightning? they told thats what the factory puts in. i thought ngk were the ones i needed? any info?

 

check this chart: http://www.nhtoc.com/forum/showthrea...threadid=19160

 

seeing as your stock you shold be fine but if you start to mod pull those out
plat holds to much heat

 

I used the autolites for about 10 minutes. Terrible idle and bad all around if you ask me. I later emailed Autolite and they told me they do not make a spark plug for our trucks. They also told me to print the email they sent me and take it to the local parts store where I got them. I did and I believe they have since updated their computers. I'd take em out if you have already put them in and go with NGK TR6's that's what I've got and I love em!

 

I have 8 autolite racing AR 94's(2 heat ranges colder) sitting in my desk draw that is the right application for my truck w/ the mods that I have.