hey guys id like to know what is a good nitro engine for the savage 21 , i turned it into a shelf queen , i thought i would make it stronger by replacing all stock plastic parts with aluminum/titanium and never thought about the added extra weight . well when i finally fired it up i noticed right away how the stock engine struggled to get it jumping and moving all that weight so its time for a new engine anyway I'm looking for something with a little more power to get this up to stock speed, i really don't want so much power that it chews up the gears and spurs. any ideas ?