Number one has a partial VIN which is most common, number two has the full VIN which (I think) was only used in the '69 model year.

They're both from '69 cars, number one is from a car built at the Lynch Road plant so it's from a B body. Number two is from a Dart built at the Los Angeles plant; the P engine designator is for the 340 and it should have a shorter tail housing which accounts for the difference in weight.

More info:

http://www.slantsix.org/articles/4-speeds/ODA833fourspeed1.htm