Crummy, just a follow up note that the "date casting codes" for both the block and head will be cast raised letters/numbers instead of stamped in like the serial number.
Take a look at fellow Stovebolter
tclederman's 235/261 decoding web page. He has great pictures and info on where to find them and how to read/decode what the date codes mean. All credit to Tim for his resource info!
Helpful hint - Chevrolet used a capital letter as the first character to denote the "month" in these codes. A = January, B = February, etc...
