Tamiya Monster Beetle/Mud Baster/Blackfoot

[mxdame]

Need some advice on beefing up the gear box on my MB as am re building it & want to get more power into it. Starting off with a sports tuned motor but want to go brushless & want to know if it is best to lock the diff & if so best way to do it. I was thinking about removing the center pin & getting a small long screw to hold the diff together. Any advice from someone who has go brushless on a MB/MB/BF would be appreciated. Is there after market metal gears for them?