gears

Hello , I have a vintage monter beetle , and just put a castle 7700kv brushless set up with a mamba max pro esc. My question is what size pinion gear should I use and where can I upgrade the other trans gears. I also have a thorpe trans with plastic gears , should I upgrade to steel gears and if so what ? Thankx for the support '=) Joe

Now the question is , when I drive foward is sounds like the gears are spinning , but in reverse no problem ? I know I have a broke wheel adaptor but it is tight . In forward there is a clacking sound at time but in reverse no noise and smooth . I have a programable esc , maybe the punch is set to high? Any help would be appreicated , thank you '=) Joe