Isnt that just the cap that goes under the rotor? On older vehicles it was used to protect the points from unknowing people playing with them and messing up dwell. My 4.5 has been without one for a very long time and it runs fine.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k