what are these called and where can I find them

what are these called and where can I find them

66Dvert said
they aren't sill plates for sure

Excuse me? :poke:

1963-66 Valiant, Dart, 4 Door and Wagon Left Rear Sill Plate – National Mo-Parts
Sill Plates, 63-66 A-Body Dart Barracuda Valiant - Pair - CHASIL636 - Vans Auto
Mopar NOS 1963-66 Valiant, Dart, 4 Door and Wagon Left Rear Sill Plate 2292057 | eBay