idk man. i used to be sponsered by my local rc shop and all we ran was savages for nitro monster truck class. some of the hpi fans that are nitro guys will know the shop. its pree well famous. high octane hobbies? youtube it and youll see the hell we put those truck threw. shop is closed now
new owners didnt do so well. that and the first and original owner had some money him self that id imagine helded to keep the store afloat. ol well. anyways youtube high octane hobbies and youll see. savages can go threw hell.
also when i was racing my 2003 hpi savage 25. i had a stock chassis, with traxxas zombies and rpm offset wheels. thing ran great. dialed my shocks in to the point where it wouldnt bounce and she did amazing. also for your friend thats blown his diffs. tell him to put thicker oil in it and hell find he can get a limited slip diff from it, im talking 50 000 weight oil, the stuff you have to use pliars to squeeze the bottle to get it out. also litium grease in with the ring and pinion does wonders