Was just scrolling thru the new 09 FRPP catalog and they now have 2 different sets of cnc ported 3v heads, the old style 05-08 with the 16mm plugs and the new style 08-09 with 12mm plugs. They also have a pics of the new 12mm plugs, they look skinnier (smaller diameter) and have threads almost all the way down the plug housing. They mention that the base part # on the coil packs are different, so I'm guessing that the heads, plugs, and coil packs are different on the new style.

If I knew how to copy and paste from a pdf file, I'd show you the pic. Until then just download your own copy of the 09 frpp catalog. Once you have the catalog, the heads and plugs are on page 89.

http://www.fordracingparts.com/downl...gs/2009-pp.zip

 

From what I was told by Troyer (looking into some plugs they recommended), there is a double letter designation on some late 08's that confirms a revised plug design. The double letters were something like "BH" and "BB" (don't quote me) and one or the other was the new set-up void of the problems. Unfortunately, my 2008 built mid-May 2008 still has the old design... I think.

 

I thought the new head/plug design cut off date was October 2007.

What options are available for replacement plugs for a stock 07 5.4? I'm going to attempt the plug change and hope to put something in that wont have issues in the future.

 

That is what I had read as well.

 

if your coil boots are brown it is the new style, if the coil boots are black they are the old style.

 

The type of plug can be identified by checking for one of these numbers on the top of the coils.

Engines with late style 12 mm spark
plugs can be identified by coil engineering
number 8L3E. Engines with early style 16 mm
“High Thread” design spark plugs can be
identified by coil engineering number 3L3E.

 

excellent info, thanks.

 

SW- You definitely shouldn't have the old style if you have a May '08 build. That is near the end of the '08 model year. I have also read what several others have said, Oct. '07 was the change. When you look up the plugs for your '08 they are definitely showing the 12MM (new) plug. If the production date for the new heads and plug is Oct '07, there is a possibility the very 1st. '08's had the old plugs and heads. Ford has always had a habit of carrying over or using early, parts. Not necessarily cutting off the change at the model year change.