plug gap, increase or reduce?

Leo,
0.080" plug gaps were specced in 1974 for 455 Pontiac engines. That was years before Plat/Irid/Ytrrium/Ruthenium electrodes saw the light of day.
I have a NGK flier release for their Irid plugs, 1994.
It reads: 'NGK have recently released their new range of Iridium....