Can I trust it, it's from the United Kingdom, you have to down load it or read it for one month for free.  It would be helpful in more ways than one, if it included instructions for all dealer accessories.

http://logisticsbooks.co.uk/file-ready/1966-chevrolet-accessories-installation-manual-ss-impala-biscayne-bel-air-caprice-full-size-wagons-chevelle-malibu-el-camino-chevy-ii-nova-corvair-chevy-van-sportvan-suburban-and-pickup-truck-66-chevy