Brisk Silver Racing spark plugs are a better option than Denso or NGK iridium spark plugs for those wanting a plug that’s pre-gapped and offers maximum performance. Stock LF4 spark plugs are AC Delco 41-147, 12662396, iridium, gapped between .030 and .035″. These are approximately two heat ranges colder than stock, have projected tips just like OEM and come pre-gapped in the sweet spot of .026 to .028”.
Brisk Silver Racing spark plugs have a better ignitability than conventional performance spark plugs, and offer better performance and reliability in high boost, nitrous or high compression applications. Silver is an element with the most free electrons, and is the best electrical and thermal (heat) conductor of all metals! Better than gold, copper …and many times better than Iridium. The Brisk Silver Racing plugs have a fine wire center electrode (not just the tip), which gives more room for insulator between the center electrode and spark plug shell. More insulation results in a durable spark plug with high dielectric strength, which is the most important spark plug parameter in forced induction applications.
When you replace the spark plugs, always apply anti-seize to the spark plug threads and dielectric grease on the inside of the coil pack connector boots. This will ensure the plugs can be easily removed in the future and displace the air inside the rubber boots, which will in turn prevent carbon tracking and misfires under boost.
* Recommended torque value when installing in aluminum cylinder heads is 8 to 14 foot-pounds.