I have a day cab, and if I don't make it home, THIS is my sleeper: Anything smaller and I just can't get comfortable.
I installed numerous sleepers on day cabs. Some easy as popping out rear window of cab, others get the Sawzall out the make a walk in. All you need is room on the frame. Cheapest one was scoring a vintage Mercury sleeper for $300 and mounting it on a S Series IHC.
That's not a coffin box,with a coffin box the cut out in the sleeper was the same size as the window.
I know, they're half the size, but couldn't find a picture. Googled all over the place and still couldn't find one. I've seen some on the older Mack's.
I basically have what he’s looking for. A 36” bunk on a 379. Gotta get out the truck to cjange your mind!
In the oilfield we still use those coffins. Pete 365's with 32's not even your standard 36in I'm 5'6 so I doesn't bug me but one of our drivers was 6'5 or so and even he could fit
I did a sleeper remove and replace though...it had a 36" and I put a 60" Aerodyne on and opened the hole up to Peterbilt Unibilt size so I could get the seat back further. I utilized that Saturday/Sunday morning as me and my boy took a ride and ended up staying out longer than expected...I gave up my nice pillowtop mattress and I reclined my chair and slept in it nicely with it reclined back all the way.
Don't they make sleepers that simply sit behind the cab, and are accessed from the sides or back of the sleeper? I could swear I have seen doors on the sides and backs of sleepers.