The bottom line of the 66 Suburban VIN tag relates totally to the vehicle it was installed on:
C= 2WD
14 = half ton standard Wheelbase
6 = Suburban
6 = 1966
Z = Fremont California
Serial Number of production
The upper line relates to the BID number C=Chevrolet, 66 is the calendar year of the bid, and 157 is the sequential number of the bid for that year.