The purpose of water injection on many of the acft in the early 60s (P-3As & some P-3Bs). If not that, then adding a movable cambered inboard leading edge slat (in addition to the outer slats) a la TA-3B & EKA-3B. Without the CLEO wing on the EKA-3B, takeoffs (from land bases with runways shorter than 11,000 feet) had to be done early in the morning before the temp got above 80.