Hi everybody. My name is Nick Russell and my wife and I have been fulltime RVers for over 8 years. We live and travel in a 40 foot MCI bus that we converted ourselves. If anybody is interested in the conversion process, you can see a complete story on it on our website at www.gypsyjournal.net.
Lately we have been talking about a new project, building a truck conversion toy hauler. We like the Volvo Class 8 trucks, but are flexible on what truck to get. I have a ton of questions, but will start with a couple:

1 - We spend a lot of time around Elkhart, Indiana. Does anybody know of shops in that area that could stretch a frame and maybe build a box to our specs?

2 - Any idea what stretching a frame to get a conversion with an overall length of 40 feet would coast?

3 - For those of you with Renegade or Haulmark
type truck conversions, what kind of fuel mileage can one expect?

Nick, IMO, if you can afford to go with a new truck, do it.
I'm building a 33ft rig (overall 43') on a Freightliner Columbia. There were 14 pages of spec sheets on the cab and chassis. Many of the spec's are specific to building it into a motorhome.
Just to highlight a few: The frame (already stretched from Freightliner) is doubled ft to back; the ft axle is rated @ 16,000lbs (vs 12,000 as rated on most used tractors), the rear gear ratio is compatible to a motorhome ie, better fuel economy (vs low ratio in typical used tractor that hauls 90,000 lbs down the road); and,...it's already equipped with rear air-suspension, stretched driveline, stretched wiring, exhaust, etc.
Then, consider 500k mile & 7 year warranty.
There aren't many dealers that have the knowlege to spec out a truck for "motorhome" cab & chassis purposes. Most of the "boys" in Elkhart get theirs through Freightliner in Springfield, Illinois (John Patkunis is the sales rep in the know).
I had the shell built @ Hawk Engineering in Jackson, Mo. (www.hawkengineering.com)
I liked his fabrication methods & ideas better than anyone else.
He built the cage from 1&1/2" square tubing on 16" centers, uses .050" alum skins, 3/4" ply for {walk-on} roof. (1.5" sq tubing allows for ample insulation space)
Also, he uses a lot of other "better than average" materials & very tight construction tolerances which also sold me.
I'm finishing the interior and wanted the shell absolutely square & plumb,...which it is!
As for fuel milage,...It's equipped with a 450 Mercedes & Eaton 10spd auto-shift,...I drove it from Jackson, Mo to OKC, Ok (aprox 600 miles) through the back roads (and bucking a 25mph head wind) average speed 70mph,...& got 10mpg. The truck only had 500 miles on it & it's tight. I would expect the mpg to improve after it's been through the breakin period.
The Mercedes is probably the most fuel efficient engine out there at this time and the auto-shift trans is smarter than the average driver, which also makes the chore of driving much more pleasent.
Again,...this is just my humble opinion.

Thanks for the info, Bob. Sounds like you have it planned out pretty well.

Unfortunately, a new truck isn't in our budget, but I sure wish it was.