Losi 8ight brushless

I just put a 8XL in my losi 8ight I will be running a 4s lipo and for right now I have a Mamba max esc running it. I will later get a quark monster esc but it may be a while, but I was wondering if anyone could give me an idea what pinion gear to run for the best performance. I want speed but I don't want to over heat the motor or esc. Any advice would be greatly appreciated. Thanks