I'm not able to locate a George Bismark Foster, married to Ola Kathleen Mundy in the 1940 census records by name search. I know they were still alive because I have found an April 27, 1942 WWII draft registration card that lists them both as living at 4237 University Blvd., Dallas, Dallas County, Texas. According to George's death certificate, they moved to Dallas in 1934. Therefore, I think it is very likely that for the 1940 census they were living in Dallas, and that it was probably also at 4237 University Blvd in 1940.
Therefore, I'd like to find the 1940 census records for University Blvd in Dallas and search the page to try and find their record.
Using Ancestry.com or FamilySearch.org, how can I locate the 1940 census pages for that street in Dallas? Is there an index by location I can use? Can I determine the voting district and use that to find the right pages?