A hulking, 261-foot-tall outpatient surgery center planned for Memorial Sloan-Kettering Cancer Center would free up the hospital's main building for critical procedures by creating new space for less intensive surgeries, the hospital claims. Sloan-Kettering estimates the extension will help an estimated 60 patients a day. But residents in the co-op next door at 440 East 62nd St. are saying the boxy 172,000-square-foot facility would be so close to them it would block daylight.