I've been researching all I can about conversion of a dual HDT rear to a single for towing a 5th. I haven't seen anything about people purchasing a stock single axle HDT so they wouldn't have to mess with having a conversion done. Can anyone offer any input on why most don't just but a stock single axle HDT instead of a dual for conversion? Thanks.

Because it is difficult to find the type of HDT that is well suited for an RV toter in single axle. There are simply not many singles out there. If you can find one int he model truck you want then that is a great way to go. But you limit the "universe" of eligable trucks so much by only looking at singles that it is not practical for most. There is no big deal in converting over to a single IF you know what has to be done and monitor the process carefully.

Thanks Jack. I saw some singles when I was looking at www.truckpaper.com but I have not looked at any up close yet. I was thinking that most of the singles were set up with stick shift and made for "short haul" runs (i.e. regional carriers). I definately want an HDT due to the long life of the drivetrain and the ability to tow anything safely. I want to take one and convert it to a multiple passenger by gutting the sleeper and adding captains chairs and bench seats, 1 or 2 doors for passenger access, windows, and an A/V entertainment system for the passengers. Basically turn it into a suburban on steroids I will build the bed with an air hitch and possibly make it a hydraulic tilt bed with removable sides so it can be used to haul like a pickup when not used for towing (I would have a bolt on cover to protect the hitch). A set of Super Singles on the rear instead of the dual rear tires would round it out.  Basically it would be the "last truck you ever need" since the HDT's are designed to go for well over 1 million miles before a major overhaul. Your thoughts?

My comments, in no particular order...

- I don't recommend super singles on a truck with a single rear axle. It is a safety issue, for one thing. If you loose a tire you will have a real problem. I don't believe Michelin recommends that either. I do know that most tire dealers will not mount a SS on a single rear axle.

- There is enough room in an HDT for easy passenger ingress/egress through the passenger door. It is typically not required to add doors.

- it is relatively easy to turn a sleeper into seating. The easiest is a jackknife sofa in the rear. This allows 4-across adult seating. If you want to pull out the storage areas then it is far more work...you have AC/heating for the sleeper under there. But it can be re-located if required. If you want both a bench seat and separate captains chairs then you need to look at 770's, KW T2000, or Pete 387 in the aero trucks. A Volvo 610/630 does not have enough cab space for both. IMO an aero truck is the best RV hauler. Conventionals are too long in wheelbase, turn poorly, and are hard to see out of. But any truck COULD work...some are just better than others.

- Windows on a Volvo are pretty easy. There is a cutout on the back for day cab windows on all of the sleepers (same cab back panel is used on the day cabs). It is easy to add smaller side windows. Larger side windows require cutting the side braces for the cab structure and relocating them. They can not be totally eliminated.

- You  are correct that you are unlikely to find an automated trans in a factory single. Not that they do not exist, but they are statistically rare...I would not limit myself to the factory single market. The first task is to find the right truck...single or not. Consider single a bonus. You might want to buy a truck from someone on the SKP forum. There are some good trucks on there from time-to-time. Already converted and with some usage history.