The engine is 12/05 so it's a 18 mm

I believe this is the P/N you need, for 18mm gaskets. This is the P/N for ONE SIDE. It should be just gaskets and the stupid TTY bolts. If you order them online and need them shipped, you can call and request to have the bolts taken out to save on shipping too. The gaskets are universal so you can use them on either side.

4C3Z-6051-EB

Your best bet is to call with your VIN when ordering the gaskets though, just to make sure you're getting what you need. I scored mine on ebay for $200 shipped for both sides, brand new.

So will I still have the same chance of blowing a gasket with new ones as the old ones or have they enhanced the quality of them. Regaurdless I'll be putting new ones on when I'm getting the new work done I just like to know what I'm working with

The gaskets themselves were never the problem. They blow due to the crappy design of 4 bolts per cylinder, and the use of TTY (torque to yield) bolts. The bolts are torqued down beyond their yield strength, so they become very "stretchy" if you will. The idea was to allow it to flex some to absorb heat/stress etc, except they stretch too much and the gaskets pop. Add to this, Ford's spec for flatness of the heads, and more importantly, how they call that spec out and measure it, flat out sucks. Even brand new heads from Ford should be taken to a machine shop and decked flat. Flat heads, flat block, and studs with good OEM gaskets are the best recipe available to us.

For those who want to get crazy, GoGo diesel can get you copper head gaskets in any thickness you want...