If the production number of 1,126 1966 Chevy K10 swb truck, is, in fact, accurate, I would say this puts your truck in the "rare" category. The only matching numbers you will find are the last 12 characters of the VIN will be found on the driver side frame rail, in two locations. Congratulations on your truck and welcome to the stovebolt.
Follow this link for production numbers:
'60-'66 Chevy truck production numbers 
