Stingers I believe are 20T motors, which feel like decent stock motors in speeds.
You could pickup a 14T modified and be faster, as well as getting better batteries and better connectors. Even a good quality 19T motor will be significantly faster than the stinger.
Me personally, I would sell the esc and motor for whatever I could get, and go with a mamba max 5700 brushless setup. Its 180 from bpp, and will give you excellent speeds, and you don't have any real maintenance to do on the motor compared to brushed motors. The ESC can also do brushed motors if you need to use one.
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