Block Numbers

[280bb0]

hey guys need your help looking at a challenger that has a 340 in it can anyone tell me the info on the block number are 2780830-340- ? 5 or 2 or the letter S    any help would be great
                                             
                                                             Thanks  Brian

[John_Kunkel]

2780(9)30-340 is the casting number for all '68-'73 340 blocks, the dash number following the 340 is a foundry index number.

The engine serial number is stamped on the front of the block on the drivers side just below the head, a partial VIN is stamped in a machined flat just above the pan gasket on the passenger side. The block VIN should match the VIN tag on the dash is it's the original block.