On my '71 Dart GT (2 dr hardtop) with bucket seats:
Front:
C10 x2= front lap belt retractors (mounted to the inside of the sill)
C11 x2= shoulder belt anchors on the hardtop
C12 x2= front seat buckle ends (on the tunnel)
Rear:
C10 x2: outer belts mounted on the sills
C12 x2: inner belts mounted to the floor
