ive never used a heavy wieght like this before

[blueb8llz]

i'm using 120k diff oil and have never used one this heavy before and wanted to know how you're supposed to apply it. since it's so thick are you supposed to apply it onto the gears like grease and let it move around inside the diff? or if you're supposed to fill the cup, how much are you supposed to fill? it's hard to tell since it's so tight in the diff. any tips?
if it matters, i have a 3905 emaxx.
i bought 120k and a 50k. im planning to put 120k in the front diff and mix the 120 and 50 to get 85k for the rear diff. im runnning bl power and when i accelerate, my emaxx pulls to one side. i was told if i put heavier diff oil, it should help with that problem. stock comes with 30k
my bashing consists of mainly climbing hills, rocks, etc, and trampling over things..not much speed runs.
or should i put the 85k in the front diffs and 50k in the rear?