Need a 4x4 K5 frame measurement

[AJs72K5]

On the rear of the frame, right where it levels out behind the wheel well... is the measurement from top frame rail to bottom frame rail the same as it is at the back of the frame? I think its different on a 2wd, but need to confirm that its the same on a 4x4. Hopefully that makes sense.... and yes, I know this is a truck frame, but you get the idea.



Thanks!