Best Spark Plug For P Heads?

[ZephyrEFI]

So, apparently I made the silly mistake of buying plugs for the E7 application, but the P heads use different plugs.

I'm told that for best performance and to not confuse the computer, I should use copper plugs. I'm looking around and it doesn't look like Motorcraft even makes copper plugs for this application. There is nickel, but not copper.

So, what have you found that works best with P heads? I've always stuck to Motorcraft for reasonably good quality (even if their products probably are just made by the highest bidder) and to keep things easy and consistent. Should I do that here? Is nickel as good as copper? What other brands do you like?

[ukravit]

I use Autolite 104 Copper Resistor Spark Plug.
No issues so far.

[Two86fiveoh's]

X2. Autolite all the way.

[ZephyrEFI]

Works for me, thanks!

Sent from my SM-G960U using Tapatalk

[xctasy]

Your not running EDIS6, so you have to revert to TFi, non GT40P spec Autolite 104's and have them pre gapped at 42 thou.

1993 MN12 Thunderbird & Cougar/Mustang Cobra SVT/ EBII GT spec.

Aussie reference is
https://www.maceengineering.com.au/e...roducts/C605-8

When going EDIS, there are other issues to contend with that work in with GT40P heads; 50000 mile durability and lifelong spark durability requires a better type pf material, but unless you've got EDIS8 firepower, not an issue for you.

Use the spec that suits the ignition

[ZephyrEFI]

42, you mean gap them like a Motorcraft 42C, correct?

Sent from my SM-G960U using Tapatalk

[854vragtop]

NGK V-Power gapped at .054". (Part # TR55 for GT40P-heads). Take a look at the close up picture of the center electrode in the link below. Electricity loves to jump off or attach to sharp, pointy objects. With the V cut, you have a lot more sharp edges than without it. And, another good thing is that they're relative cheap too.

https://shop.advanceautoparts.com/p/...951/19650153-P

I'm running an MSD 6AL box too. When I lived up in Seattle, one of the guys behind the counter at a locally owned auto parts store said all the guys at the drag strip ran NGK V-power plugs in their 5.0L foxbody Mustangs. That's when I tried them and I've been using them ever since (~25 years now) both in my E5 heads and now the P heads.

[ZephyrEFI]

Cool, thanks! It might come down to which recommended brand the store has in stock!

[mcb82gt]

https://www.rockauto.com/en/catalog/...park+plug,7212

[ZephyrEFI]

I wanted to go to Advance because that's where I bought the Motorcrafts I needed to return. Plus then, I didn't need to wait. I did order my Motorcraft cap, rotor, and air filter from Rockauto though because I couldn't find them locally.