And here FYI is the dimensional data on the pinbox itself (including width though I fail to understand how that enters into the equation at hand); the Escape 5.0 uses OEM model 1716 / replacement model L07.
The only 'missing' dimension is from the centerline of the kingpin to the front edge of the pinbox bearing plate; on mine that measures 5-1/8".
Between the this and the already linked ETI info you should have all the answers to your question, hope that helps.
Just curious, care to share what specific truck / bed you are evaluating? There's always the possibility a member here has experience with that specific rig they will share.