650cc Breast Implants to Get C or D Cups?

I agree 650cc implants are quite large, too often people think size is everything in breast surgery. However, shape is the most important. Consider a second opionon to discuss other surgical options

Perhaps this may be helpful. Generally, if a woman wears a size 36 AB bra and would like to be a C cup, which is the average size that women wear and the average size bra that is sold, she needs a volume of approximately 350 to 390 cc to make that change. This becomes less if she's wearing a 34 bra, because it has a smaller strap size and the cups have a smaller diameter. A smaller diameter implant would then be a volume of approximately 300 to 350 cc. In the same way if she was more petite, maybe a double zero or size one and wore a 32 AB bra, then to become a 32C cup she would only require about 250 to 300 cc. The profile is determined by the amount of projection versus roundness that the you desire, as well as the size of the implant and size of your chest. Also, the placement or incision location will also have an effect on profile. Your Plastic Surgeon will measure you to determine the best shape, size and placement of the #implants to be used.

One of the most important discussions facing breast
augmentation patients is the size of breast implants that will be used. Most
patients are striving for harmony, balance, and proportion with the surrounding
anatomic structures. Typically they want a natural look with some fullness in
the upper breast area. Most patients tend to speak in terms of cup size.
Unfortunately cup size is not always helpful because manufacturers of bras
label their products differently and women don’t always wear their bras the
same way. In other words, some women wear their bras snugly, while others wear
them loosely. This creates communication problems when talking cup size. It’s
virtually impossible to translate cup size into CC’s for this reason.In an effort to determine breast size in a more
objective manner, we utilize external silicone sizers and the Vectra 3D
computer imaging system. External silicone sizers are designed to sit on top of
the patient’s breasts. They can be held against the patient’s chest or placed
inside the patient’s bra. This technique helps the patient visualize what their
breasts will look like with a specific sized implant. It also gives them a
sense of the volume that will sit on their chest wall and how it feels.The Vectra 3D imaging system is a relatively new
technology that we’ve found to be extremely helpful for determining breast
implant size. This system allows patients to visualize different sized implants
on their actual body. Patients find this to be extremely helpful.The ability to visualize your projected surgical result
alleviates much of the anxiety associated with this procedure. The use of
external sizers and the Vectra 3D imaging system accomplishes this goal. It’s
important to remember that final adjustments in the size of breast implants
will ultimately be made in the operating room depending on anatomic factors.

This may be large however I recommend you try on a variety of sizers at your next consultation to see what works for you. You may find that 650cc may actually give you a good result. 

At 5'7" 165 lbs theoretically anything over 400cc would achieve a C cup.  There multiple implant styles that can achieve the look you desire.  I recommend searching out a experienced, board certified plastic surgeon for another consultation.  There are some critical measurements that are performed to help determine the best implant for you.  These need to be done by someone experienced.  The distance in between your breasts is not likely to be conquered by using a larger implants and is part of the measurements taken into consideration during a consultation.