The maximum takeoff weight for a Boeing 707 was 247,000 lb or 123.5 tons.
American Airlines Flight 11 (which hit the North Tower) was a Boeing 767-223ER and has maximum takeoff weight of 395,000 lb or 197.5 tons
United Airlines Flight 175 (which hit the South Tower) was a Boeing 767-200 and also has maximum takeoff weight of 395,000 lb or 197.5 tons
Vulcan Stev's Database 