It's not so much the threads on the plug. Its the threads on the cylinder heads that are a problem. I think the rolled threads aren't "deep" enough to bite into the threads in the aluminum heads. Ends up pulling the threads clean out of the heads.
Then that makes rolled threads a weak point, don't it? lol It's funny. MIllions of vehicles runnin around for decades with aluminum heads and standard, non rolled threads don't have a problem blowing plugs out. That's decades and millions. Then along comes the three valve triton with something "different". But yeah, that "ain't" the problem. lol
