If your school doesn't have weighting or "A+'s" then doing something that would sacrifice your quality of life and ultimately impede your happiness for a 96 over a 94 is not worth it. Instead you should work hard throughout the year to have the 96 and do extra credit in something you enjoy. Every school has different weighting, so on your transcript there will always be an attached segment explaining how your schools grading works for the college to see. That way you won't be screwed over by other kids at different schools who have a different system. I say work hard to do the best within your own schools system, and rank / compare yourself to other classmates when thinking of college, but don't take it as far as becoming the kid who spits in other peoples lab results to screw up their future.
Work hard, stay happy, know you've done all you possibly can with what you are given because nobody can ask for more.