From 1970-72, GM issued a protect-o-plate with each car. It was a metal credit card-like device with information about the car embossed on it. The name of the original purchaser was added to it by the dealer using a special plastic labeling tape. This card was used for warranty purposes.
The information on the card can be decoded as follows:
1. VIN of the car 2. Engine number 3. Rear axle number 4. Transmission number 5. 1 here=pwr steering-N40 6. 1 here=power brakes-J50 7. 3 here=radio-U63 or-U69 8. 1 here=air cond-C60 9. Carburetor type: (H=Holley, R=Rochester,C=Carter, B=Bay City) 10. Month 1970-71(1-9 are Jan-Sept, O=Oct, N=Nov, D=Dec) 1972(A-L for Jan-Dec) 11. Chevy Bowtie