Engine Decoding HELP!!!

Ok- So, could anyone help me to decipher my engine numbers?
'67 Barracuda Formula S
273 - Commando

on the drivers side: 2806030 - 273 - 2
on the passengers: 10-13-66 clock at midnight/ noon
on the front of the block, below the heads C273 12-20 (this number is very worn and extremely difficult to read- looks like the stamp wasn't very deep to begin with. I could be missing a couple of numbers, but it's the best I can do...

ANy help would be much appreciated. From what I have been able to find is this:
1) most of the casting info I have read suggests the 2806030 is a 318, but IT SAYS 273!
2) 10-13-66 means the engine was built on October 13, 1966. My car is a '67.
3) I know the C273 means (1967)(273).

Does anyone know if there are any other numbers that I am missing?- I can't find a VIN anywhere!!! This stuff is confusing...

Thanks in advance!!:read2: