Yes they should be 4100-4200 with low IR.

In mod buggy the way I see it if you don't have enough power just drop a turn for motor.

In stock this isn't possible so this is where I think the 4600-70C with proper mAh will excel in.

For mod the 4300-50C that is coming out in 10 days or so will be fine.

I wouldn't run a short case in TC Mod or SC.