Im no numbers Guru but this is what i found in the Parts Interchange Manual.....
PK = kokomo plant
2801543 = 1967 Polara, Monaco, Newport, Polica Package w/ 383, 1968 Belvedere, Coronet, Charger, Fury, Monaco, Polara and Newport with 383 2bbl
2337 = build date, I would assume March 23, 1967?
0938 = daily sequential number