Maybe with a homemade cooled EGR system the pinging would go away despite the 0.093 Quench Clearance.

Maybe with an internal hole drilled from the interior of the intake manifold plenum into a runner at just the right angle, the swirl would increase enough that the quench jet action would not be needed.

Maybe with the right fuel injector cleaner amount added to every tank of fuel the combustion chamber surfaces would stay cleaner of carbon deposits and peak chamber temperatures would drop enough to eliminate pinging.

Almost certainly water/methanol injection like Aquamist would eliminate the pinging and increase power with cooler cylinder filling.