Plugs for SBC
 

Up to this point I've run what ever plug Delco recommended for a 350 truck engine. What plug would be recommended for a 409 SBC? Right now my plugs are black and wet so I'm sure the jetting is off, but I may be running too cool a plug too. How do I tell the heat range of a plug. Is it in the number, or listed somewhere else. Thanks guys.