regarding smaller Medium trucks,
I don't know much about the U.S but here in Oz there are plenty of converted box truck motorhomes getting around now. I've now converted 4, 5 ton sized pantecs (box) trucks over the years. Down here Japanese COE models are the best option. My last one (1992 model) was a 4ltr turbo diesel 10 speed Ford/Mazda had good highway legs cruised at 110kph (70ish mph) 3000rpm all day at around 18-20 mpg.
At this medium size, box flat chassis rails are normal with box sizes ranging from 10ft up to 20ft in 2ft increments. Headroom up to 12ft (plenty of room for a single bloke) even have cabover bed space. (known as luton peaks)
mine has a 1in steel box frame above the wooden hardwood floor (tallow wood) with alloy sheet external covering.
I reckon most over your way are gasser engines though, Isuzu, Hino's come to mind.
Geoff

https://www.truckconversion.net/forum...w-garage-7555/


The accordion gasket is on the build thread and my loft has plenty of room

Where are the pictures of your conversions?

Sam

I love my retired UHaul with a 7.3 IDI diesel and a 5 speed manual she is not fast but will cruise all day at 60-65... At 10-12 MPG...

My requirements were pretty simple... 16' garage for my jeep... And a real mattress and AC for me...

The build was fun... And continues as I am ready to sell her... And move to an even bigger rig so I can run coast to coast ...

Bydesign I love that you have the passion for building your truck. I was asking roKWiz about his convertions..... you know they are upside down and backwards.....LOL

Sam