I have a 2010 Silverado, 5.3 and 4x4 with the 6spd auto. I towed my boat this weekend through some of the Hill Country in TX (outside temp in 90's) and my trans temp went up to 205. How high is acceptable before I need to start worrying? On the highway where it was flatter it stayed down around 180. I had on the tow/haul mode, and was taking it relatively easy. The boat/trailer weighs under 6,000 lbs. which I wouldn't think is "pushing it" for this truck. Thanks in advance!