2003 Dodge 2500 Hemi towing improvement advice

I own a 2003 1500 HEMI 4X2 with the 3.55's and tow all day long 60-65....with a 7000lb+ trailer in tow. I do kick down into 2nd on some of the steeper grades and down to 50mph...if the steep hills last too long, mine too will kick down into 1st at which point I just get out of it so it will hang back in 2nd gear....sometimes down to 40mph but not that often.
Mine has 116,000 on the clock, and has one rearend rebuild....at 92K.