Dave, I am restoring a '63 Plymouth and the parts are finished just like any later year B and E-bodies from what I have found. Natural upper and lowers (lowers cosmolene dipped), black torsion bars, etc...

'70 Super Bee 440 6 pack 4-spd 4.10 Dana N96 EB5
‘70 Super Bee 440 6 pack 4-spd 3.54 Dana FC7
‘70 ‘Cuda 440+6bbl 4-spd 3.54 Dana N96 EB5 V1W