They did the same thing on the MD-11, the aircraft is longer and the stab smaller. The DC10 had a tenancy to pitch up upon spoiler extension but not as violently as the -11 and of course the longer airframe means an easier tail strike. The fix was restricting full spoiler deflection until the nose was on the ground. Still I had a 35 year Captain come off an MD-11 completely disheveled a few weeks ago as he had one run away from him and almost struck the tail. Who knows? A ground sense glitch, environmental factors. All checked good for us and the aircraft has flown W/O incident since. A quick check with Mr. Boeing says that the -8 is 20 feet longer than the -400.