Hey Dale fan- according to the catalog, your VIN decodes as follows:
C- Chevy division
C- conventional cab
Z-350 diesel motor in 1980
1- half ton
4- pick up body type
A-Year (1980)
J- assembly plant- Janesville
132,838- sequence number of your truck...probably the 32,838 th truck produced that year. Hope this helps you out some.