Very good question. The reason why I had a strong feeling about this is that the majority of the high TENS have been found between serial numbers 3500 and 4000. I can think of 20 or so that fall into that serial number break down and I only know of one that falls out of that range, but I sure that there are more.
I will try and break down the roation for you. Yes CW on the front of the engine is CCW when looking at the back if the trans or pinion gear. So now looking at it from the rear, if the ring gear was on the left side of the pinion, the top of the ring gear would go towards the front of the machine. If the ring gear was on the right side of the pinion the top of the ring gear would go towards the rear. Does this make sense? If it does, please keep reading.
From this point forward we will look at the side view of the left final drive with the front of the machine to the left.
With the ring gear on the left of the pinion we have stated that the the top of the ring gear will move towards the front of the machine. Now with our new view point (left side of the machine) that would be CCW. CCW through the brake drum and to the small drive gear. The bull gear and the sprocket would be CW for a standard ten at this time, which is the wrong direction. Therefore if the ring gear is on the left of the pinion it would be for a High Clearance tractor. There is a third gear in the HC final drives. That changes the bull gear and sprocket rotation back to CCW, which is the correct rotation for the view point that I have explained. Does all of this make sense?