C5AE A Block 427?

Just pulled engine out of old 58 Tbird looking for a 390. It has later model miss matched heads on it. Block says C5AE A Rods are C3AE C crank is C4AE?. Any one know what this is for sure?

If I recall correctly, Ford's letters are as follows:

A = 4
B = 5
C = 6
D = 7
E = 8
F = 9
G = 0 (2000)

So, a part with "C3ae" would be from '63.