Has anyone decoded their 340 serial number?

9/29/71 or even 8/29/71 would make it a 1972 model year engine at the earliest... what color were those supposed to be? Wasn't as though the big 3 had much of an idea regarding JIT inventory back then or rotating stock. Wouldn't be the first block to sit around a year + before being assembled.

Original paint? Yeah sure, that's it. LOL Not a chance with the casting date and model year designations.

The first 3 on the front of block could possibly be a "J"