Which plug in head and cam engine?

[2002_red_gts]

What the best plug that I should run? My engine is a 10:5.1 comp with Greg good heads and cam. From what I've read I've come down to 2 plugs
Ngk
ZFR5F11 stock heat range.
ZFR6F-11 which is a step colder

Both have the needed extended tips on them


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[99RT10&GTS]

Just get the ZFR6F, don't get the -11. I believe the -11 means the plug is pre-gapped to .044. You will want to gap your plugs at .030-.032.

[Jack B]

What is wrong with the RC12ECC

[2002_red_gts]

Originally Posted by 99RT10&GTS

Just get the ZFR6F, don't get the -11. I believe the -11 means the plug is pre-gapped to .044. You will want to gap your plugs at .030-.032.

Will do. Do you think the step colder will make me lose power at all or it will be so small I shouldn't worry about it


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[plumcrazy]

I dont think its about losing power with plugs as much as how well it will run. or foul them

[99RT10&GTS]

Originally Posted by plumcrazy

I dont think its about losing power with plugs as much as how well it will run. or foul them

Correct. And Jack B is correct, you could use the stock heat range and be just fine. The RC12ECC is a great plug!

[primedtsi]

Im running tr6-ix (stock # 3689) in mine with the blower. IX is for iridium.

[ViperTony]

I use the stock plug RC12ECC gapped at .030 per Greg.

[Jack B]

Originally Posted by ViperTony

I use the stock plug RC12ECC gapped at .030 per Greg.

That is a Hard pIug to improve upon for a NA car.

[ViperTony]

Originally Posted by Jack B

That is a Hard pIug to improve upon for a NA car.

Cheap too. I've had no issues with these plugs on my setup. Greg seems to know what he's talking about.