O.K. got the answers on the stretch. Show Hauler uses BRT or Sellers Mfg depending on the type of stretch required. I spoke to both companies directly for the answers.
For my truck BRT will do the stretch and will require approximately a 10' section added. They will cut the frame in the middle of the present length from the back of the cab to the back end of the frame. The 10' section will be added and welded at the ends.(No overlap, butted end to end) Since road trucks like mine use a slightly thinner walled frame material versus say a box truck, they will run a second channel the complete length of each frame rail. This is bolted at each cross member section and any other through points. In some applications welding will be used, depending on the stretch length, frame rail thickness and the application. Both companies mention that welding versus bolting is far stronger, if done properly. I asked about manufacturers putting the no welding sticker on the frame. If to high a heat is achieved on the steel then it will begin to lose its tensile strength. Basically you need to know what you are doing. (This would also cover a manufaturer against liability if a non professional where to weld on a chassis) As far as carrier bearings go, they both use each chassis manufacturer's specification to determine this, Freightliner recommends every 65".
Both companies have been doing this for along time (40 yrs for Sellers) and have never had a bent or broken frame due to their work.
Bill
2003 28' Show Hauler Motorhome on a 1995 FL 120 completely refurbished chassis.
Currently in production - scheduled completion 12/10/02 www.showhauler.com
[This message was edited by warpath on October 16, 2002 at 10:47 AM.]