I don't believe there is a name per se. In the factory there was some sealant in there to (I assume) keep water from entering the car. I actually believe there was a gasket on the inside plate which pushed out when the hinge was bolted on. I do not believe this is something that is reproduced or is available, but I could be wrong.
70 Challenger RT 440-6 EFI, 73 Cuda 416-6 EFI
05 Hemi Durango, 01 Ram 4x4, 14 Ram 2500 4X4, 10 PCP Challenger 6 spd RT, 01 Viper GTS ACR, 52 B3B w/330 Desoto Hemi, 70 Hemi RR (under const)
9 x Challengers. AAR Cuda, 4 RR, 2 GTX, 4 Chargers, etc... (too many to list)