1978 sportsman RV. Seized 440 and transmission gone. Dana 70? (I think) under rear.

I inherited this rig for free, with hopes to make a killer flatbed truck, but it was too far rotted, wires cut, stuff bashed to hell, etc.

My next thoughts were to salvage the chassis to make a killer trailer, but this leads me to my question.

Was this motorhome built on a truck chassis, or was the frame specifically made for the RV only?

If I could swap another cab onto the truck, that may change my plans.

Thanks in advance,
'
eightlitermopar