From the CRG 1967 cowl tag decoding link -
"The very first 1967 Z28's and L78's were also coded 4P; the 4L and 4K codes were then used on the remainder of 1967 Z28 and L78 production.
The lack of a 4P, 4L, 4N, or 4K code indicates the car originally had a 327 (assuming the car had a V8, as indicated by the VIN). The only exception is the early SS350's noted above."
Applies to both Los Angeles and Norwood if I read it correctly -
Regards,
Steve