Controversy in engine block decoding

[Recian]

So I found the engine code for my truck. It's a 81 pickup. The block is numbers matching. I found the Vin stamped with the engine code. The engine code is T0311UDB. This makes no sense because it's numbers matching but this engine code UDB says it's a 83 305. Anyone come across this?

[ray_mcavoy]

Did you happen to look up the suffix code on the www.nastyz28.com website by any chance? If so, their listing only shows the final year "FY" that a particular code was used.

So that year listing is just saying the "UDB" suffix code was last used in 1983, not that it's an 83 engine.

[Recian]

Ok that makes sense now. I was on nastyz28.com for the decoding and They didnt get into much detail on their site about the year codes.

[geezer#99]

Check the casting date behind the pass side head on the bellhousing flange. The last number is the year your motor was built.