1999 spark plugs
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
in my opinion it really doesn't matter if you use a 41-110, denso 5090 or ngk iridium.
all are top notch plugs, the delco plugs also use an identical looking, and possibly the same electrode as denso...which makes you wonder since denso was the OE plug in the z06
best value plug is the denso 5090 which are a hair under $5 each on rock auto. vatozone also does rebates on ac delco often at $2 a plug bringing them down to $5 a plug as well
"My Dad's a TV Repairman"
Joined: Jul 2014
Posts: 471
Likes: 153
From: San Diego
41-985 has been discontinued, new number is 41-110
in my opinion it really doesn't matter if you use a 41-110, denso 5090 or ngk iridium.
all are top notch plugs, the delco plugs also use an identical looking, and possibly the same electrode as denso...which makes you wonder since denso was the OE plug in the z06
best value plug is the denso 5090 which are a hair under $5 each on rock auto. vatozone also does rebates on ac delco often at $2 a plug bringing them down to $5 a plug as well
in my opinion it really doesn't matter if you use a 41-110, denso 5090 or ngk iridium.
all are top notch plugs, the delco plugs also use an identical looking, and possibly the same electrode as denso...which makes you wonder since denso was the OE plug in the z06
best value plug is the denso 5090 which are a hair under $5 each on rock auto. vatozone also does rebates on ac delco often at $2 a plug bringing them down to $5 a plug as well
True, although sets of 8 of the 41-985s are still available all over for cheap bucks ($30 to $40 on the 'bay for example).
I like my NGKs- what's your opinion on the new .40 gap they're shipped with? Would you consider bumping them up to .55 or so?
Thanks
Race Director
Joined: Jan 2008
Posts: 16,028
Likes: 170
From: oregon
.55 would work on e85 or a mild race gas but it's just too dicey on pump and worth at most 3-5hp
some of the plugs, older ones mainly, were gapped at .44 which as large as i would go on pump
Racer
Joined: Mar 2011
Posts: 420
Likes: 13
From: West Deptford NJ
I've run NGK TR-55 for two years and recently started to experience some detonation on pump gas. They are gapped at .55. Did not know any better. Thanks for the info.
Last edited by jlaw1313@comcast.net; Aug 29, 2014 at 09:56 AM.
Melting Slicks
Joined: Aug 2013
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