I am looking to buy an 03/04 Cobra and have heard people saying that there is a difference in the heads between 03 and 04. Is that true? What is the differences between the two? Thanks for the advice.
No it is not true, ALL stock production heads for 03 and o4 had a design flaw, specifically only four threads for the plugs. This leads to spark plug blowout. In 2005 a new head design was released with nine threads. Some people CLAIM that their Terminator came stock with nine threads but I do not believe it since the redesigned heads were not released until after Terminator production had ceased. If a Terminator truly has nine threads then it has to have been a replaced head using the new design.
Also, people will say that you can count the turns it takes to seat the plug to determine the threads, that makes about as much sense as a plane not being able to take off while on a treadmill... The only way to determine thread count is by visual inspection of careful use of a feeler to count them.
Also, people will ramble on about blue stripes painted on the heads and such, this means NOTHING and does not indicate a certain head revision. It was a mark used on the line for some obscure purpose, not related to the part number or revision level.
Thanks for the heads up. I do have another question though, I found a red 04 through a dealer. He says that after the car warms up for 10 minutes or so there is a small tick in the heads. He says that there is a service bulletin from Ford stating that this is fairly normal. I cant seem to find the bulletin, have you guys heard anything about this? Thanks!!