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.