1971 was the year that GM changed from LOF Safety Plate to Safety Flo-Lite. So early cars will have the safety plate glass while later cars recieved the Flo-Lite.
AMERICAN STANDARD RATINGS:
Windshield = AS1
Door Glass = AS2
Rear Window (Coupe) = AS2
Rear Window (Hard Top) = AS4 (plastic)
Rear Window (Soft Top) = AS6
GLASS DATE CODES:
The glass was also coded by date of manufacture. The first symbol denotes the month while the second denotes the year. Glass used on 1971 models most likely will have been manufactured in 1970 (T) or 1971 (N).
The date codes are as follows:
| NT | JAN 1970 | NN | JAN 1971 |
| XT | FEB 1970 | XN | FEB 1971 |
| LT | MAR 1970 | LN | MAR 1971 |
| GT | APR 1970 | GN | APR 1971 |
| JT | MAY 1970 | JN | MAY 1971 |
| IT | JUN 1970 | IN | JUN 1971 |
| UT | JUL 1970 | UN | JUL 1971 |
| TT | AUG 1970 | TN | AUG 1971 |
| AT | SEP 1970 | AN | SEP 1971 |
| YT | OCT 1970 | YN | OCT 1971 |
| CT | NOV 1970 | CN | NOV 1971 |
| VT | DEC 1970 | VN | DEC 1971 |