I have a real bad habit of putting my feet on the dash while we're posted. I hate our Chevys, no room to put them up there!
I'm 5'8" and have plenty of room in my usual unit. It's an 03 or 04 E450. My partner likes to sit with her back against the dash and feet up on the shelves under the pass-through. I tried it, just a little bit too tall. Damn! haha
In our Chev type 1(normal unit) I can't get my feet up but I can curl up against the door and be comfy. Sprinters I can put my feet up and stretch.
Fords depend on where the bulkhead wall is. We have a couple spare units with about a foot of space before the wall and I can lean back and put my head against the side behind the door- and it's padded like a built in pillow. Love that spare truck.