i also thinking front use 30000 as well, but atomic recommend front less stiff will be better.
at first i use front 30000 and rear 10000, just normal setting like my gp. but it doesnt work we ...
wait.........
we wont use 30000 and 10000 at the ball diff.....
we use 30000 on the suspension only
for ball diff
we will use associate or kyosho ball diff grease