Originally Posted by snrusnak
Nicolas, I'm not sure if you're aware but the 4.7L uses different plugs top and bottom. Bottom are iridiums and tops are nickel yttrium. I believe they are both bosch.
Here are the part numbers and prices(just got a quote from mopar parts).
SPARKPLUG [Part# SPFR8TE2AA]
Your Price:$3.51 x8
SPARKPLUG [Part# SPFR8TI332]
Your Price:$6.15 x8
Prices are each plus shipping of approx 13.xx within continental US
I'm also looking for a colder plug top and bottom, if you find them let me know, as I came up empty handed. I've been wondering if there would be any benefit(or if it'd hurt) by switching the top plug to iridium.
The coils are batch fire(fire both plugs at the same time). Some claim that the difference in plug material causes a delayed spark to one of the plugs, so the spark occurs at different times, and this is for performance. I don't know if that's true or not so not sure if changing the top plug to the same material as the bottom would have a good or bad effect, or no effect.
Manual says to replace uppers at ~50,000 miles and lowers at ~100,000 miles.
Thanks, ill keep looking around but im in no hurry.
I wonder why the guys that have 03-07 4.7l with ngc just put the 08 motor in. all sensors match up as far as I've seen. Use adapter plates for throttle body. I don't know, just seems like that's what I would of done.. Sct tuners would really help this motor out.