Colder Spark Plugs Stop Pinging?

My dart sport 360 will sometimes detonate/ping in warm hot weather. Engine is a stock stroke 360. It is a hot street set up. 340 X-heads, 292/508 mopar cam, KB107 flat top pistons. 340 Victor intake 850 thermoquad off an ex drag race Cuda so it is modified with fatter jets and such. 727 transmission with a turbo action street strip valve body, 9.5" FTI 3400-3600 stall converter. 8.25 rear with 3.91's and an Auburn sure grip unit. Car runs strong and sweet. But have to run 93 octane fuel and will add a bottle of stp octane boost. But it seems to not do much for octane. I have disconnected vacuum advance and car runs strong still but helps somewhat to reduce the ping. Will colder plugs help?