It looks to be an 84 block, if I am reading the 10k day calendar correctly.
If you look on the side of the block, there should be a date and a clock cast into the block.
Here is a 94 Magnum that shows it on the passenger side, but I think the earlier blocks had it on the driver side.
http://www.netwalk.com/~ericv/images/408_stroker/pages/engine_bd1%20019_jpg.htm