2003 Dodge 2500 Hemi towing improvement advice

I really think its gearing. The truck is a 4 door long bed 4x4 so it's very heavy and the 5 speed in these trucks is geared awful. At work I have a f250 with the 5.4 and 3.73'sand my buddy at work has the same truck but it came with 4.10's. His truck runs so much better than mine and gets 2 mpg more. So if funds permit in the future 4.56's would help a lot I think.