Man, Deep Sand, 600 Feet High, 38 degree angle Is one Big Ass Dune. I wouldn't pull a 15 tooth front sprocket it unless it way over 100 horsepower.
I could only pull 3rd gear hard before and I was making about 60 horsepower before and that was with a 3.23 to 1 Ratio. (13/42) so I am gearing up allot from before. ChokeCherry is Extreme this is why I will start with Stock. Most people that run this hill with only a piped shee can make it up it in 2nd gear.
Hot running Shee can pull 4th gear with 14/43 so if I am little better than that stock should gain me some more top speed and Still have the power to pull this Hill.
If I was out in the Open Desert I would run tall gears, but not On ChokeCherry in St Anthony Id, You need to see this Hill.