Ok, my goal is to get lower gearing in my 40. From what I've read, ~100:1, is near ideal for most wheeling. I'm still running a 2f, 4spd case and 4.11 axles. The AA rock box, with my stock drivetrain, seems like the least expensive option and would get me to 98:1. The Marlin toy box, 4.7:1, would get me 134:1, but would end up costing me several hundred more. I haven't heard of problems with either of them yet. What would you do?