Art, I go along with Carey. I don't downshift unless it starts to hunt back and forth. You should be fine down I-95, not much for hills.
Use common sense, and all should be fine. Keep your fluids changed often. Oil is cheap insurance. I just hit 147,000 miles on my transmission without a problem. Change my fluid each year, and have been using Amsoil synthetic the past two years. Keep it cool.
Tom McCauley (DP Member #513)
"Tankers-ToyII" Loaded 05 D/A K-3500 CC, SRW. Deep pan on Allison w/Transyn. Edge Juice w/attitude, 4" Kennedy exhaust, 98 Gal. Transfer-Flow cross bed fuel tank, Leer 100XQ bed cap. Reese 14,000lb class V hitch w/ dual cam HP sway control. Tow 34ft. 32FKD Holiday Rambler travel trailer. GCW 20,360lbs