I looked under the geographic area and didn’t see a block option, and also just didn’t see a way to convert the data.
Due to confidentiality restrictions, we do not offer any public use microdata at the block level. The smallest unit of geography available are PUMAs (Public Use Microdata Areas), which are areas with at least 100,000 residents.
If summary data will provide the information you need, NHGIS is a project within the IPUMS family that provides block level data for 2000 and 2010. The data comes in the form of summary tables, and depending on your research needs, this may be an appropriate solution for you.
To help you convert the data, I recommend watching our tutorial videos and checking out our FAQ page. If you have any more questions, the user support teams at ipums@umn.edu and nhgis@umn.edu are always happy to help.
Hope this helps.