Not sure if you mean 4g total or each at those locations...
What I would advise is to refer to the TW University Power Potential tool and the Sweet Zone Size tool. They will let you know where the "gaps" or "weaknesses" exist... and give you an idea of how to improve them.
Personally, I have done quite extensive modifications on mine (you can see all the details in the Head G360+ Extreme Tour thread). I usually get a 4 3/8 grip and add two overgrips (first with almost no overlap, and the second as standard). Initially, I also added 5.6g of weight at 7" above the butt cap (top of grip), and possibly some weight inside the butt cap (I can't remember now, but it will be in that thread), and then at various points throughout the head (2,3,4,8,9,10, and 12 o'clock). In total, I spread 5.5-6g around the head of the racquet, and around 15.6g on the handle.
Later, I removed the 5.6g from the top of the handle and what I put inside the butt cap... and replaced it with silicone in the handle (which added 15g more to the handle). I kept the weights added to the head. My current specs are (dependent on strings used): 362g strung, 315mm balance, and an increased SW (estimate around 335-340 SW - never fully measured).
Obviously, all these things are dependent on personal preferences, what you're trying to achieve, and what specs you are used to (most of my racquets are 350g+ static weight... and closer to 360g). That is the reason I advised you to look at those Tools in the TW University section.
Finally, I would advise you to spread the weight you put around the head (not just 3 and 9... but halve what you would have put there and add it to 2 and 10 as well... so if you were going to put 2g total at 3... I would put 1 or 1.5g at 3 and the rest at 2, then repeat the process on the other side). I also like putting weight at 12, as it lifts the sweet zone and makes sure that the racquet is not dead feeling towards the top of the hoop/head.
Hope that helps (sorry for the long answer).