So I put plugs a little while back in one of my 98's and NAPA didn't have the correct champions. So I had to go with autolites. Then when I went to do the '01 they didn't have the ngk so I got champions. Lol. Now I'm thinking I want to get the ngk's for the 01 and maybe put the champions (rc12ecc) into the 98. Any problem running the ECC in the 98 instead of the LYC? Going to put the autolites in my other 98 which isn't on the road yet. The 98 that has the autolites in it currently, actually had ecc's when I got it from the PO. it is misfiring slightly in cylinder 1 due to a valve issue and I'm running an ECC in cylinder 1 only hoping to compensate for it running slightly rich sometimes. So has this had any negative affect on the motor?

Why are you so concerned about the brand of spark plug? Changing brands is not going to make a noticeable difference as long as you have the correct spec for your model and year. Just run what you installed and forget it.

I think somewhere I read that guys running 99-01 or 00-01 found NGK ran better but our 98s fire best with Champs.

And my 1998 runs just fine with autolites. Whenever I read these spark plug threads there are several "opinions" of what is best. And opinions seem to be based primarily on brand bias. Perhaps there are many people out there who think they can somehow optimize their performance with one brand or another. I've yet to find a vehicle that noticeably changed its performance due to a brand change.

Longevity.

I have never had an Autolite fail and have gotten over 100K miles out of my last set.

They are now in both my Jeeps.

I use the ZFR5Ns even in my Renix Jeeps.

ZFR5N here

Champs were the go-to plug in Mopars since the 40's, but I had some problems with them in my 00 WJ so I switched to NGK and no more problems. Thank you Cruiser54 for your recommendation a year ago.