magnum EQ spark plugs?

[maca]

Hey guys
A friend of mine is running a 360 Magnum with EQ heads. It has around 360 hp at the flywheel. What would be a good plug for the eq heads and should he go one heat range cooler at that hp. The cheapest and most common plug here in Australia is the NGK brand.
Cheers

 

[Lelo Dart]

NGK 4291 are what I plan on trying on with a 9.2:1 Magnum engine but the heads are Pro-Comp iron but are similar to the EQ's. The NGK 7252 are are also good on Magnum engine and are comparable to the Autolite 3923 which are popular and I like too. Hope this helps.

 

[maca]

Thanks
The heat range 6 and gap 1.1mm will be ok for my hp?

 

[Lelo Dart]

Sorry don't know mm. Gap at .040 . Heat range has more to do with compression ratio than HP.

 

[TrailBeast]

Thanks
The heat range 6 and gap 1.1mm will be ok for my hp?

1.1mm=.043 and should be fine as long as the ignition is up to that gap.
I sure wouldn't go that big with a stock Mopar box ignition on an over stock compression engine though.
Also just a note that the EQ heads use the small size (peanut plug) that Lelo Dart seems to be aware of due to the numbers he posted.

 

[maca]

We are running a distributor with a 4 pin bosch module powered by a GT40 coil.
I will install the 1.1mm plugs and try them. I guess if they are too wide they will break down in the high rpm. Then i could try .9mm
If needed.
Comp is 9.1 so hopefully heat range 6 will be ok

 

[67 gt]

maca these are what I use on mine 1 step colder , can get these from Repco or super **** Auto, I run plug gap @ 45 HEI electronic ignition, mild 318 9.7 comp using 98 premium Fuel.

 

[maca]

Thanks mate