I am running a msd 6 al box. I have been gapping the plugs at .050. This seems to be the max gap that the tip of the plug can be massaged to. I run champion 404 's . I have tried to gap to .060 , even with my special " gapping" tool, the tip can't retain the squareness to the electrode. I also retired all oil filled coils. I run an ecoil.