Wow, good on him! I wouldn't stress too much about what the tin says about recommended feeds... all babies are different and some just have big tummies to fill!
FWIW my first bub used to drink an entire bottle every hour instead of every 3 hours like the tin says, I worried about her but she never drank so much that she made herself sick, she just stacked on heaps of weight and it all fell off the minute she started walking... she's an amazingly healthy almost-3-yo now and is tall and skinny like her dad
Your little man was a good size at birth (my DD1 was about the same!) and I guess some babies just love having a full belly - if he's sleeping well, not spewing too much and is having no problems filling his nappy, I'd say you're doing it just fine He will adjust his feeding and probably drop right off at some point, whether it's weeks or months. HTH