CensusCD NCDB has a subset of the Long Form data for 1970, 1980 and 1990 (and 2000 Short Form data). To see the variables which are available for each decade go to the following page http://www.uscensus.net/CensusCD40Years/censuscd40.htm#variables GeoLytics also offers the full census for these periods (CensusCD 1970; CensusCD 1980; and CensusCD 1990+ Maps) which offer the complete Long Form data sets for 1970, 1980 and 1990 with the additional data; 1980 and 1990 also have additional geographic selections. But only the NCDB product has the data normalized to 2000 boundaries. Information about these data sets, variable lists, geographies and pricing is available at http://www.uscensus.net.
The price for CensusCD NCDB is $1,595 for the nation and $845 for a single state. This will include the Short Form version and a free upgrade to the Long Form version when it becomes available (about 6-8 weeks).
For each of these data sets, the data has been compressed so that it fits on 1 disk and it comes with built-in mapping capabilities. With a few quick keystrokes you can generate full-blown maps or tables. You can export the file data into other systems such as statistical (e.g. SAS, SPSS), database (e.g. Access, Oracle), spreadsheet (e.g. Excel, 1-2-3), and mapping (e.g. Arc View, MapInfo) packages.
Note: Tracts do not cover 100% of the geographic areas in 1970, or even in 1980, as they do in 1990 and 2000. Tracts in 1970 are found mainly in urban areas. There is complete coverage at the county or MCD level in 1970 and 1980 but this is only available on the full census products not the NCDB.