I have Both a Redcat Volcano EPX Pro and a HSP 94111 Brontosaurus. They're basically the same MT.
My Brontosaurus is going through the "Change of Life," you might say. it was originally a Brushed vertical. What I did was take the Brushless System out of the Redcat Volcano and installed it in the Brontosaurus.
it ran pretty good for about a year and a half with a Brass 17T MOD .6 3.17 bore size Pinion and a plastic Nylon 64T Spur gear.
Now, I'm going to seriously mod this thing to fit a boat size motor with a 5mm dia. shaft to handle a Steel 21T MOD .6 5mm Bore Pinion coupled to a Steel 64T Spur to start off with.
Other changes like Aluminum hub carriers and CV's to come later. I blinged out the Volcano, but I just want to do just what's neccessary to the Brontosaurus.