Hey Bob!
I know you have a factory United unit- any chance you could do me a big favor and give me the interior dimensions (depth and height) of the sleeper over your cab? I've been snooping in a few of those type trucks, but did not have a tape measure with me. I know they have just an adequate amount of headroom and depth to function as a bunk. My scheme would be to have a deeper bunk so I can have a walk in cutout into the cab maybe 18", and still have a usable bunk forward of that. Using a factory job like yours a reference would help me with figuring if my idea is feasible. I know pony express does a cutout just like I want into the roof of the truck like I want to do, but they use a regular depth on the sleeper and a wedge shaped drop in board to fill it in to convert to a bunk, and some funky custom made cushions to piece together the mattress. I'd rather just make everything permanent and use a regular mattress.
Thanks! Dave
here is a link to the pony express brochure showing their walk in:
http://www.hgrstrailer.com/pdf/pony_.../toterhome.pdf