As Jeeptug said before he deleted his post, the F-150 (pre-2004) sucked bigtime in crash tests partially b/c of it's mass and velocity. Regardless, they had horrible ratings, and I definitely wouldn't have wanted to be in a big crash in an F-150. They have addressed this problem, and are now rated much higher. Colorado is right, regardless of the comparrison, you didn't have much chance in an old F-150. Here is a link w/crash results from pre-04 F-150s and the 04 F-150.
http://msnbc.msn.com/id/3738415/