I used 86/31 for my gear ratio. It should be 5.08 instead of 5.2. My friend told me to use 115/39 which is 5.38. The speed is excellent and run time is more than 10min. with Panasonic (Black).
As far as durability wise, You either use the BRP Front Bumper to help protect the A-arms or just stock tons of A-arms.