"If I begin with a Freightliner Columbia 112 (tandum rear axels), will I still be under 40' total length with 30 feet of cabin"
The dealer should be able to tell you the length of the cab yes? I think the cab is a few feet longer than 10'. The back of cab to front bumber of my E350 Box Van is 7' I think and the Freightliner truck is much bigger than my box van.
You can add another variable, turning radius of the truck you will build on?
Does anyone have info re turning radiuses of different trucks?
What are the problems with long overhangs? Is it the smashing of poles and fire hydrants on the sidewalk when you pull out?
Stuff that would happen to me?
How does overhang affect towing? Any?
What will the 17' living space layout be? What kind of rear ramp/lift will you be using? Will the mini's tires be at the same level as the cabin floor?
Is there a computer program for overhang, wheelbase and turn radius?
A mini in a conversion will be extra cool. Couple of motorcycles and personal watercraft also?
Let us know what you find out.