At that age, he should be given as much as he can eat. We've got one that age at the shelter who weighs 600 grams, and he's getting at least one 200 gram can of food a day spread over 4 - 5 meals and has dry available at all times. They need a lot of energy for growth.
When we got our little "Hannah" last Aug she weighed in at 1.9 lbs at 8 wks. I started her on Royal Canin Kitten food, she just did wonderful on this food, basically she let me know when she was hungry. She started gaining weight and her coat just had such a beautiful shine within a few weeks. Good luck with your new baby!!