Are you considering a 2007 Dodge 3500? If so, I would wait for the 2008 if you are planning on purchasing one with the Cummins Turbo Diesel. Reason being, Dodge quit manufacturing the 5.9 liter engine as of 31 Dec 2006. Once those trucks are sold there will not be anymore dually pick-up trucks available until the 2008 model year. Dodge is currently producing a 2007 RAM 3500 chassis cab with the new 6.7 liter Cummins engine. This new engine is the strongest yet in a diesel offered by Dodge/Cummins. (See the Dodge.com web page for specs). The new truck comes with the six speed manual and the new six speed Aisine automatic which is rated to tow more than the manual transmission. The new engine and transmission comes with a variable flow turbo (see Dodge website) and a tow/haul switch for the transmissiion that activates the transmission to downshift and the automatice exhaust brake to apply when going downhill. Personally, if I were going to buy a new truck (and I may) I would wait for the 2008 model to come out. I currently tow at 35RLTS Cedar Creek with a 2001 RAM 2500 Club Cab 4x4 with the CTD and four speed auto and have had no problems with the transmission. However, I do not "horse it" and have installed a U.S. Gear exhaust brake that works really well with the auto. It positions the brake father downstream in the exhaust system (right in front of the resonator) so that when it is applied it takes a little for the back pressure to build before it starts slowing the truck. The benefit of this brake is it does not immediately retard speed as does the PacBrake or Banks Brake which cause undue stress on the automatic transmission's input shaft. The D'cellerator Brake by US Gear eases into the slow down thereby reducing the stress on the transmiision input shaft.