Here's the way your Cowl Tag / VIN break down. As mentioned before, there is no way to determine a true SS (RPO Z03) from the Cowl Tag / VIN data by itself. If you can find a build sheet or have a Protecto-Plate, you would find RPO Z03 listed here indicating the SS package. If the car does have Bucket Seats, SS Door Panels, Console, "Supersport" emblem on the dash, along with the Super Sport emblems on the Grille, Trunk Lid, and front Fenders under the Impala script, then it's probably a pretty good bet that the car is a true SS. It really wouldn't be cost effective for someone to add all of these things to a non-SS Impala in an effort to make a few more bucks offf of the sale of the car.
Body Style: 2-Dr Sport Coupe
Engine: 8 Cyl
Interior Color: Gold
Lower Body Color: Palomino Ivory
Upper Body Color: Ash Gold