Why not a RB v12 or OS .12 tz? They wont suck as much fuel as the .18 will and for a stadium truck, has more than enough kick. Unless you like running wide open throttle for a block or 2, flipping it and then running it down.
I have both engines and they are top shelf engines. The traxxas 2.5r is mid shelf, traxxas put that pos plastic carb on it and its the weak point. Cracks and you spend days tryn to figure out whats going on with it. Easy fix, OS .18tm carb off of ebay for 20-30 bucks and it runs all day and the next flawlessly.