[njohnson6425]

I need to find out where I can get some colder heat range plugs for my 2008 gt. The thread pattern is 12mm. The 2005-2007 heads are different then the 2008-2009, They use 14mm threads. Does anyone know where I can get them From.

[ITLRUN]

Any local parts store, and try Denso Iridium they work great. They're a little costly, but well worth the money, Mike. SCT Tuner.

[jaja6009]

WHy are you going to a colder plug? Its not needed unless you are adding a power adder. Im just curious. When I added colder plugs to my car before I added my blower there was some detonation confirmed by the dealership. Once the blower was added the car ran great. I still cant figure why the car detonated with colder plugs. But colder plugs on the stock engine is a waste of money. They will foul easier too on a stock engine. Are you adding some nitrous?

[stlwagon]

www.brenspeed.com has them.