Yesterday saw the launch of the 1875 Valuation Rolls on ScotlandsPeople. These will assist you in locating your ancestors between the 1871 and 1881 census years. As an introduction, viewing the index pages will be free until the end of the year (December 31). To view the record itself will cost 2 credits.
Here's the link: http://www.scotlandspeople.gov.uk/content/help/index.aspx?r=554&2080