I have never heard any conclusive proof about the cylinder heads being changed because of the spark-plug-blowout problems... If anyone has any, I'd be first in line to check it out

The only difference people have noted is the number of threads on the SPARK PLUG have been increased.

The 100K tuneup interval is the root cause of the spark-plug-blowout (among other things). If they were removed and re-torqued (and anti-siezed and sealed with dialectric grease) at 20K intervals the plug blowout problems would probably be mostly gone. And the rest would be solved by improved assembly-line quality-control on the plug torque.

Some of the plug blowouts were caused by leaky heater hose connections (the dreaded #4 (or #5 on a V10) misfire if left too long). Others are by the extremely long tuneup interval. Still others are caused by too much moisture getting down into the hole.

None of these situations has anything to do with the head design. Of course, putting inserts in instead of tapping the aluminum head would help somewhat

Using the timesert seems to be the general consensus on here, and no one has come back to report a problem with it afterwards.

I would suggest, if you go the timesert route, get the OTHER PLUGS changed and torqued correctly at the same time. Make sure they use anti-sieze and dialectric grease on everything.

art k.