For simplicity, find a world formula cam, springs, and carb. Add the wf head for a little more flow and compression.
Or get the whole motor.
Faster motors offers a superstock kit which offers a couple more hp over stock, with no machine work required.
Keep in mind, like a street car, the more radical the setup, the more time you will spend working on it vs riding it.
You will find kart racers try to promote our sport as being done by responsible, respecting individuals.
Part of that is riding on closed courses not open to other traffic.
Please try to not make kart racers look like a bunch of hooligans.
Thanks