I got my first arrma, and i have to say its very good and well made.I watched a lot of videos and i decide to get typhon.I ran it whit 4s 70c whit stock pinion, i will do only parks and litlle jumps.Should i change the diff oil or maybe shimm the diffs or i keep it stock? I don't want to change anything before it brakes.Sorry for english its not my first language.