Hey,
So here is the deal, I have an 09 mustang 4.6..and i bought the HT1's for my saleen kit. Well here is the deal. THEY DONT FIT!! hahaha, i guess ford changed the plug size..HOW AWESOME! Man o man, well anyways, im just about ready to get it running, well i need some plugs that are a degree colder than stock..and will fit an 09 Mustang gt, PLEASE HELP ASAP!!!

 

Just be happy your 4.6 engine has the revised heads. My 08 Shelby does not. The change was for the better and happened in late 07, maybe 3-4 months after the start of the 08 MY.

 

Well it doesnt do me any good. I need to know what plugs i can go buy right now that will work in my car. I looked for the NGK Iridiums, and they tried to sell me a different one , its Iridium, but a different park number. Does anyone know what plug i can go buy at auto zone or napa or schucks or wherever. I just need some dang spark plugs TODAY

 

Ford Racing M-12405-3V12MM

 

where can i pick a set of those up is the problem man..

 

I would say your supplier is a moron. Pretty common knowledge the 4.6 heads changed in Dec 07 so they only use the 1 piece plug. The brown boot is the new design. Now hopefully your supplier will get you the proper heat range since you're FI.

 

In a way i am happy i have the old head and in a way i feel i am cursed, seeing as ford sees this as a problem for the customer since the plugs should not be changed until the car has reached the 100K mile mark. If it was not for the fear of having to remove the head if something goes wrong i would be changing my plugs at 30K miles which is coming up soon.

I hope you got all of this worked out.

 

Go to www.brenspeed.com and order some from them. They carry all that in stock.