Auggie is right. I did the math myself and found the same. You can change the gearing but you'll need a chain and gears. However D&D sells a 74 pitch chain 13wide which is as wide as the stock chain that you may be able to use. In their catalog it is 47$. So if you used a 26 tooth gear it would come out to a 72.5pitch chain needed and you should gain 7-8mph on top end I don't know how much it would hurt the sled off the line though. If you know how to do the math for the gearing you can play around with different ratios to get more top speed.
I did some playing with the numbers you gave a 25/38 will work and a gain of 6-7mph on top end with a 72 pitch chain.
I did some playing with the numbers you gave a 25/38 will work and a gain of 6-7mph on top end with a 72 pitch chain.
