Bed gets skinny?

[MarkEkberg]

Trying to build a slide in for kids to sleep in. Had one when I was a kid. Took measurements from the tailgate end of the bed. Today I tried to fit it in and found that the front of the bed is almost 3" wider at the cab v/s the tailgate.

So many times I want to slap engineers in the face.

 

[lpennock]

Should be the same on the outside also. The taper is to reduce wind drag.