frame flex/twist question

[1992gen1_fan]

Whenever driving slow through potholes or whatever un-evenness in say a driveway or dirt road I can see how much the frame flexes. On each side of the rear window I can see a section of the headache rack dip a good inch maybe close to 2" below the bottom of the rear window and the above the bottom of the window. So thats like a good 2- 3" of flex between the cab and my flatbed. That sound right?

I do have a dump bed so its hinged just behind the rear of the frame rail so I know that would amplify it but it seems like this thing flexes more that a lot of rigs I see. Does that sound normal?

[simplysmn]

Sound's Normal to me .you want flex because without it you will start snapping thing's .

[1992gen1_fan]

OK yea just making sure that much is normal . Just got to thinking today, my cab mounts are a bit loose so that probably makes the twist show more also.