Help Decoding BB 427

I just bought a 72 Chevelle with a BB chevy 427, and I got these numbers off the Block 10913CTB and 12S142868

Can anyone decode this for me?

Thanks,
Bob

Here's a list of CTB block codes, but they are small block, not big block...?????
http://www.nastyz28.com/gm-chevy-cod...s-suffix-3.php

Could the leading number be T0913? That would equate to Tonawanda plant assembly on September (09) 13

CTB suffix is a 1972 396/402 engine code that was used in Chevelles, both auto and manual transmission. Horsepower 210 - 240

Might I ask why you think it's a 427 in a 72 Chevelle?

Regards, Glenn