Those plugs look good to me, the one that is the darker color looks like it may have oil on it, is it shiny when you guys look at it or is it the picture? If it is shiny fix that, there shuld not be any oil on the plugs, they should be dull looking, not shiny It is not uncommon for both B and RB motors, especially after machining them, to have oil suck up into the intake manifold from the lifter galley due to the intake valley pan leaking or letting oil be sucked into the intake manifold One easy thing to try is the next step colder plug to help cool the combustion chambers down to help eliminate pinging What brand and heat range are those plugs? Good luck, keep the shiny side up and the greasy side down