You ought to look into the Motion Pros I posted about. "Pro Plug Sockets" If you work at the dealer, you can get em around half price through the Parts Unlimited book :thumbup:
I'm a powersports (mostly motorcycle) tech and I use these Motion Pro "Pro Plug" sockets. These only work on plugs like NGK and denso with grooved insulators. The plug uses two balls held in tension under a band of spring steel around the socket. The balls lock into the groove on the plug and...