Executives from Rudin Management and St. Vincent’s Hospital will make their case to the Landmarks Preservation Commission today for a redevelopment project, which would result in a $800 million hospital and 400 units of luxury housing in Greenwich Village. It is very unlikely that any action will be taken by the 11 commission members today on the proposed plan, which has stirred opposition from resident groups and preservationists. The plan would replace the current St. Vincent’s Hospital located on Seventh Avenue with a new 21-story hospital on a site between 12th and 13th streets. To finance the project, St. Vincent’s plans to sell several buildings to the Rudin Corporation for $310 million. The developer plans to raze the buildings and build 650,000 square feet of high-end housing, along with street-level retail space, underground parking, and medical office space. Because the area is considered a landmark, approval by the Landmarks Commission is required for the plan to move through the city’s land use review process.