Measure before you buy, the 7" drop from etrailer was not enough drop for my 1997 F450.
Every ambo box is a little different but the frame is usually alot higher then the bottom of the bumper.
The rear bumper really complicates the installation, you will more then likely have to get an extension if you keep the rear bumper. It is difficult to find a high weight capacity extension.
You won't find your answer online without getting under the truck. Hopefully you have good solid frame all the way back without any frame extensions.
Once you get it all setup the E450 will move what ever you can connect to it.