I wouldn't change a thing, he looks perfect.
Boys need more calories for longer than the girls, so keep him on the 4 cups a day until he is obviously is getting too much food, (sausage shaped rather than a slight dip in his midline viewed from above), then you can cut down to an adult maintenance portion. I see so many people limit their puppy's intake as they grow, they need the fats for their cognitive development, and the calories and nutrition to grow and mature properly. I assume you are waiting until 18-24 months to neuter? His skeletal growth will benefit from good nutrition now, and he will be a good sized boy if his parents were good sized.