How different in size will I look with 760cc after mastectomy vs a normal breast augmentation patient of my size and height?

Has a double nipples sparing mastectomy 5 months ago I currently have tissue expander in that are filled to 760cc . I am comfortable with this size but I'm nervous that when I get my implants they will look smaller due to the mastectomy. My ps has recommended tear drop textured gummy bear implants at 770 ccs