I have gone trough this, the 200 will eventually wreck the g/box, if the gears dont break the bearings will eventually give up. You have to drive it as if you drove on eggs, if you know what i mean. I went to an lt77 after several boxes later. The v8 will do the same eventually, series boxes where not designed to take that power unless driven gently, then they tend to survive. Drive it like you stole it and it will break!
Grem