Yes, per the Dodge 2009 towing guide, any transmission, gear ratio or GVWR for the 4500/5500 is still rated at 26,000 GCWR.
The 3500 cab/chassis with Asian (4. 10 only) is 12,500 GVW and 24,000 GCW.
The 3500 cab/chassis with G56/3. 42 is 12,500 GVW and only 19,000 GCW. So you are right, 3. 42 is reduced by 5,000 lbs
The 3500 cab/chassis with G56/3. 73 or 4. 10 is 12,500 GVW and 24,000 GCW.
The 4500 is offered in 15,000 or 16,500 GVW with Asian, gears are 4. 44 or 4. 88. With G56, gears are 4. 10 or 4. 44.
The 5500 with Asian is offered with 4. 88 only. The G56 is 4. 44 or 4. 88 and 19,500 GVW
Sorry, I am not smart enough to post tables or links.
Nick