Does the 04 4.6 in the new f150 have improved heads with more threads to prevent sparkplug blowout?

 

I have heard that all 03-up have them.

 

Sounds great but does anyone know for sure?

 

I know for sure that the 04/05 plugs are totally different and have over 1/2" of thread on them. The head was redesigned as well when they added the 3rd valve.
I have read on hear from a couple of Ford techs that the 03's are ok.