It's difficult to completely answer your question. It a bit more complicated than that. First of all, let me just say, you can run any size carb on any size engine and it will run. With that said, it really depends on your target purpose for the engine and what you want to get out of it. Will you run mx? XC? general trail riding? duning? Do you want absolute maximum horsepower? or just a good running engine? What rpm range is most important to you?
If you answer these questions, we can really offer better, more helpful info. And yes, I have ran this carb on my 363 mx motor.