If the fan on your 216 is as flat as the one on my '48, you might have overheating on the passes like stated above. So, you might want to camp at the base of a pass and go up very early in the morning with cooler conditions.
You probably have been through the route many times before and maybe have seen the view from the RV park at Goulding's Trading Post in Monument Valley. It is one of our favorites. You can tent camp up the hill away from the big rigs. The following shows Easter morning, 2009.
34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.