Actually it will swap in. the difference is in ride height. The 280's were real heavy, that's part of the reason for the larger displacement engine. So if you stick it in your 240 it will raise your car. If you do something to compensate for the higher ride height. You lose travel distance in your suspension. Your better off with what ya have... so keep it. If your not happy with the ride... get some new springs and strut cart's. Replace the rubber bushings with urethane stuff. This can all be had from Motorsports or Vic Brit.