Quote:
Originally Posted by DanB
Here is the difference
02-03 mach 1 and cobra heads
this was the first run of the mach1 and cobra heads, after a million complaints about excessive noise in the valve train on the drivers side ford figured they had to do something so they revised the drivers head. When the car came on to the service drive the first thing the service writer does is run TSBs to find any open complaints and the drivers head had a TSB for noise so ford started replacing them well about 2-3 months in to this they found out that they were redoing some of the cars that had already been don’t so the change the head by having then painted with a blue strip. Now this has no reworking other than some different valve guides but in fords attempt to keep the technicians from double dipping they painted the service head blue so the service writer knows if the TSB had been done or not. This head was the first head and only has 4 spark plug threads
mid 03 to end of 03 cobra and mach 1 heads
This is the 4V head that has been painted with a blue strip to show this is what ford though would take care of the excessive noise from the valve train (little did ford know that the piston slap was the cause for this noise) way to go ford !!!
This head also possesses 4 sparkplug threads
11/15/2003- 4/2004
This was the first 9 thread head
this was the 2004 cobra and the mach 1 head for 2004 this head was completely different. This was the last revision head also known as the FR500 replacement head. This head was issued some time after 11/15/2004 I have confirmed this with every 2004 cobra and mach 1 I have ever touched (approximately 50-60 cobras and 20-30 mach1s ) this head has improved ports also the coolant passages have also been changed. The only way to tell what head you have is by the thread count in the head. 9 thread signifies you have the 2004 heads and 4 thread signifies you have the 2003 heads (while nonpainted 2003 heads notes early 2003 heads) Now there is an easy test to see what heads you have seeing as how all of the threads are at the bottom coming up you can perform a simple thread count test. Start from the tight position and count the number of turns it takes to remove the sparkplug 4-5 turns means you have 4 thread and 8-9 turns means you have the 9 thread heads. if you are buying heads keep this in mind or simply contact me to buy new heads 9 thread with the improved passages 1500 a set complete new
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Interesting discussion. I have a question.
I just bought an 03. The sticker on the door says 6/03. So what heads should I have? The 4 thread ones, right?
But I count 8.5 turns when removing the spark plugs. So by your statement these are the newer heads? I have no blue stripe on my heads, just a yellow X, i think.
I'm not understanding the logic of your simple test. A spark plug for our cars has like 9 threads on it. How would it matter how many threads are in the heads? It still takes 9 full turns to fully seat a spark plug, whether there is 4 threads in the head, or 9 or 5 or 1....
Am i making sense or am i totally missing something?