Spark plug heat range

[Ardent_Z28]

I have installed Denso DNP-4713 spark plugs from Summit Racing in my engine, which have a heat range of 16. The AC Delco plugs I removed only have a number 14 on the ceramic. I tried to research if this was the heat range reference number but can't find anything in writing. All the plugs I removed have black soot that apparently didn't come clean with spark detonation, so I'm thinking the 16 heat range on the Denso iridium plugs will accomplish this without being too hot for my N/A engine. I went with Taylor Thundervolt 8.2mm wires, an upgrade from 7mm wires I removed. Does anyone know of a source I can find the heat range on the AC Delco plugs? I found a chart explaining the heat range differences and 16 seems to be the hottest to safely run in my engine, and Summit Racing references the Denso plugs are compatible to my engine.

[Injuneer]

The replacement for the stock plugs, in a relatively stock LT1 is an NGK TR55 (or TR55ix iridium). Find an equivalent to that plug in the brand you prefer, if not NGK.

Not all plug manufacturers use the same heat range designations:

https://www.sparkplugs.com/learning-center/article/116/how-do-i-find-a-colder-or-hotter-plug

[Ardent_Z28]

I found the Heat Range Cross Reference Chart in that link which shows the Denso plugs and NGK plugs have the equivalent heat range. Thanks for the information Injuneer...I appreciate it.

[zooguy]

Is your motor mainly stock what all do you have done to it your signature says deletions and mods

[Ardent_Z28]

It is all stock except the cam...Duration @ .050 intake is 220 & exhaust is 230 with 114 LSA. Beehive valve springs in the heads, so it is slightly more aggressive than stock. AIR/EGR deleted too.

[Injuneer]

You're OK w/ stock heat range.

[zooguy]

Stock heat range

[SSlowBoat]

I found the Heat Range Cross Reference Chart in that link which shows the Denso plugs and NGK plugs have the equivalent heat range. Thanks for the information Injuneer...I appreciate it.I would suggest autolite copper cores or ngk copper cores for simple na stuff. never had luck with any fancy plugs on my heads cam or cam only shtuff

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[Ardent_Z28]

This is the chart from post #3...39091
My Denso plugs (16) are the equivalent heat range as the NGK plugs (5) Injuneer mentioned. I just got the engine back on the K-member yesterday, still gotta ways to go b4 I fire it up. Hopefully these plugs will go 80k-100k miles as advertised cuz my Pacesetter LTs don't make access to 'em very easy.