The Robert Casey books are first rate.

These links are the best information I have found:

• 1LE Facts & Figures Number
• Players Challenge race cars
• 1LE Brakes - Some History
• 4th Gen Camaro Production Breakdowns
• 4th Gen Firebird Production Breakdowns
• 1LE Production counts, ish
• RPO and other fourthgen history, Brengata