If it's C2AE6015 -, it could be an FE series either a 390 or 406. BUT - it might be a late Yblock too. The suffix should tell which one.
There might be others, but this is what I found:
C2AE-B – 1962-1963, 406 FE medium-block, cross-bolted mains
C2AE-BC – 1962, 390 FE medium-block, 2-bolt mains, oil pressure relief
C2AE-BD – 1962-1963, 406 FE medium-block, cross-bolted mains
C2AE-BE – 1962, 390 FE medium-block, 2-bolt mains, oil pressure relief
C2AE-BR – 1962, 390 FE medium-block, 2-bolt mains, oil pressure relief
C2AE-BS – 1962, 390 FE medium-block, 2-bolt mains, oil pressure relief
C2AE-C – 1962-1964, 292 Y-Block small-block, 2-bolt mains
C2AE-D 1962-1963, 406 FE medium-block, cross-bolted mains
C2AE-J – 1962, 406 FE medium-block, 2-bolt mains, oil pressure relief
C2AE-K – 1962, 406 FE medium-block, 2-bolt mains, oil pressure relief
C2AE-V – 1962, 406 FE medium-block, 2-bolt mains, oil pressure relief