Quote: I switched from Champion N9YC to NGK BP6ES on my fairly stout 360 and there was a substantial improvement. I'm also running an MSD 6AL and IIRC MSD specifically recommends AGAINST running platinum plugs. I'm not sure if that is true with any other aftermarket ignition systems.
Good advice. Don't use platinums with MSD. The 12 heat range plug is too hot for 12.5-1 compression. You need the 9 series equivalent or cooler. I also like NGK or Autolite racing with the strap cut back. If you foul a 9 series plug you have some tuning issues. I recommend an Autolite AR23. -Bob
