How much clearnce between cab and cabover camper?

[brp]

I guys. I am nearing the point of hoisting my Sunrader camper body onto my F450 and I need to make final determination for how much of a gap I will have.
Obviously, less is better, as long as the two don't touch on uneven terrain.

Heimbig looks to have very little clearance, see photo. He has an F550, we both have spring mounted flatbeds, I pm'ed him looking for a measurement but got no reply.

What have you guys gone with?

4" is what I have in my head.

I would like to order my storage boxes, they take a few weeks and their height will be based on my cabover clearance. Unfortunately the truck is not at a point were I can take it out and flex things to get some actual data. ( I am midway through lifting the front 3".)

If I need to wait till that point in time I will.

Thanks again guys.

 

[BlueCoyote]

BUBB is sitting at about 4.5". Flexed up its about 2.5.

 

[brp]

Thanks Blue. Is your camper spring mounted?

 

[BlueCoyote]

Thanks Blue. Is your camper spring mounted?

Yes & No (I hear the crowd GASP already!)
The flat bed is not - however the design (open C-channel rails) is very flexible, so it flexes with the truck.
Camper is mounted on a rubber mat, there are now side box frames under the "wings", and am aware that twisty off road use will require the rear tie downs be loose. Going to make the rear guides a few inches taller, along with fabricating my own "long travel" spring rear tie downs.
In order to get the camper low enough, this was the only option.
You Ford cab appears to be taller, so you will probably be able to spring or 3 point you Sunrader.