I noticed some NGK brand ignition wires from a 4 Cylinder a few weeks ago and saw that these had bright metal heat shields attached to the silicone rubber plug boots. In my opinion that is a better design alternative than pressing the heat shields into a fit in the heads.

Was it really worth it on the Magnum V8s to use a lower quality insulation for the boots around the plug ceramic and then try to extend its working life by deflecting infra-red radiation with the pressed in metal heat shields?

I kinda suspect this was due to the 100,000 mile emissions warranty.