it just means that the car is still in its original form, including the engine and tranny.

Q: What is a "numbers matching" car?

A: A numbers matching car is a car in which the engine and transmission are marked with the same sequence number as the chassis VIN number. This number is called "the partial VIN code". Since all these parts & numbers match, they were installed at the time the car was built, and the car can be confirmed as original from this standpoint. The rearend is almost never marked with the VIN. It will have a date code on it which needs to correspond with the vehicle that's being checked. For example it can't have a date on it from AFTER the car was assembled.