To find the actual size, you'll need to:
* Look at the speakers themselves: The size is usually printed on the speaker's frame.
* Check the owner's manual: If you have the original owner's manual, it might specify speaker sizes.
* Remove the speaker grills: This is usually a simple task; carefully removing the grill will show you the size and mounting configuration of the speakers.
* Check online forums: Searching Chevy Caprice forums for your specific year and model may reveal information from other owners.
Don't rely on general assumptions; physically checking your car is the only way to be sure.