ANY TV you buy WILL slow down on hills. Notice the big trucks crawling along in the slow lane, and those are designed to tow over 80,000lbs. Do NOT expect the TV to charge up hills with the TT like it does with out a trailer. You will be disappointed no matter what you get. 3/4 tons slow down, and downshift on hills as well. I have passed many of them going up Saluda grade, and Black mountain.
IF you really want to see how well it does in the mountains. Tow the TT up 16 to Glendale Springs, or 321 to Boone. A serious test would be 226 out of Marion. However. In truth. IF you can hold 45 to 50 MPH going up Black mountain on 40, It is doing pretty good.
Honestly It sounds like your TV, and TT are pretty well matched up. No sway, and little down shifting. you didn't really expect it to stay in high gear going up the hill did you? That is pretty much unrealistic. Unless you are like my ex son in law. A flatlander from the coast. Tried to take a S10 up to Blowing Rock in 5th gear, and then thought something was wrong with it.
In short. Remember. Your 5.3 loves to rev. It makes it's power at higher RPM. Drive it like you stole it, and let it run. It will thank you for it.
Mine like to rev as well, and it sounds GREAT doing it. BTW. I always turn off 6th gear when towing. The engine likes it much better running free at a little higher RPM.
