A 1521 1y (1577kv) on 6s would be a better choice than the 1900kv 1521. These motors will make some power, that is for sure.

I have a 1521 2d in my flm savage and I destroy a diff every time i am out! I am going to try the new flux diff and the cen one to see the if they help. Also make sure you are using diff fluid, it makes a big difference.

Thanks for the tip on the Integy hubs
 

I just wanted to thank you for the heads up on the Integy rear hubs, I put some on my Savage X that is converted to brushless and I was impressed at how it simplified the whole rear of the truck. I had been like many others and always avoided their stuff, but these seem extra beefy and since you confirmed it is a high quality alloy it was a big help. I only run mine on 4s lipo around my house, so I was happy with these too as I am sure I saved a little weight and simplified maintenance. The only thing I hope is that I never have to pull the bearings out.