Sold as a set of 6 Spark Plugs:

For years we searched for the "right" plug for high HP, high boost applications on our own Zs. After testing numerous spark plugs we found the absolute best plug money can buy. Trying to find an adequate plug colder than the PFR6B-11B proved to be tough, but these plugs deliver the best spark around. BKR6, 7, 8 and 9.

Heat Ranges Available:

• The "9" heat range is the cold daddy of plugs. Recommended for extreme boost pressures (28+psi). It has weak cold performance due to fouling easily in cold conditions. Recommended to be used at the race track only (road circuit drag). The only plug to use for high boost and nitrous applications. Not recommended for daily driving.

All plugs come pre-gapped anywhere from .028' to .032", no gapping required! Simply double check the gap and your ready to go!