I have a 01 v-10 Its sole job is to tow my junk and it works well. The spark plug issue the 4.6 5.4 and 6.8 have is a simple fix. I helped design the wurth tool years ago. took a few variations but the end result is easy and simple to use. If you have the engine warm to the touch or room temp...
I have them in my frt diff(5.29). I just had the third out and after a year of hell and abuse they look great. That said it is all about the set up. My rear has yukons are still perfect after 5 years.