Hello everybody! Needs some head help.

remow2112 · Oct 25, 2010

I just scored a 1995 Mustang GT. It has the following items: E303 cam, 1.7 rockers, Cobra intake, plenum and aluminum heads. The guy I got it from had a ford tech who put the stuff on from a his busted up Cobra.

Long story short. I believe they are gt40x heads. Without tearing into the engine I used a mirror and I can see Ford racing on the front of the driver side head. Is there any way to determine they are gt40x heads without pulling a valve cover?

The car idles some what rough. When I started pulling the spark plugs I discovered that it has autolite 25 plugs. Which is great for a stock 1995 gt but is the wrong plug for the gt40x heads. I bought the autolite 104s to put in but I would like to verify the heads before I commit to the plugs.

Thanks all!

Dan...

Venomous96Cobra · Oct 25, 2010

pretty sure you will have to remove the valve cover to see the gt40x stamp. I recommend taking off the passenger side cover since it's the easier of the two to remove...

ryclef331 · Oct 26, 2010

If they're aluminum heads, regardless, you'll need the deeper reach plugs. AGAIN, as long as they're aluminum, and you can visually see the thread hole depth, and it matches up to the thread depth of the plug, it will get you close enough in the ball park to get the car running close to how it should.

remow2112 · Oct 26, 2010

Thanks for the help. It is an aluminum head and I pulled the pass side valve cover. This is what I found. From what I have found this is a 64cc head not the 58 and it has 1.7 rockers on it. So I did have the wrong spark plugs in the heads. Do they even sell this head design anymore?

Thx,
Dan...