Here are the pulley numbers for the 1966-'68 375 horse 396 which has a lot of reproduction parts so you may be able to find parts a little easier:
L78 Used a deep "V" pulley to prevent throwing belts
Crank pulley 3869978
Crank extension 3906656
Water Pump pulley 1970831
Alternator pulley 3925522
Power Steering pulley 3873847
All of these pulleys have the part number stamped into the metal.
Here is the CRG information on the BBC factory pulley list for 1968 production year (short water pump).
and here is the Long water pump pulley list (1969-'04):