ORIGINAL: HankL

Sparkplug designs with tiny & sharp center electrodes seem to be the trend of the future.

To keep the tiny electrode from melting they add the rare earth metal irridium to the alloy used. It is not pure irridium, and has platinum and other metals.

People who work in Chrysler's Dyno test room have reported that the 5.7 is within 5 degrees of 'best torque' ignition timing on 89 octane gasoline.

Using an irridium tipped sparkplug set at a wide 0.060 gap with both sparkplugs indexed so that the open gap is in the direction of the center of the cylinder and the ground post is over toward the cylinder wall is a mod worth investigating, along with a change to 93 octane gasoline for a margin of safety against detonation.

The sharp center tip, big gap and indexing
would probably increase
'fast burn'
enough to advance the 'real world' burn timing
from the factory 5 degrees past top dead center
to close to the 10-12 degrees past top dead center
where maximum torque is made
when cylinder pressure peaks at this position instead of sooner.

Want more info on 'real world' ignition timing?
This article from Australia is good:

https://dodgeforum.com/m_982171/tm.htm