I've got very large (1150cc) breast implants. Will I be able to start Crossfit? What about weight loss (30+ pounds)?

The major concern would be the length of time since your breast augmentation.  I would definitely advise you to wait three to four months following your surgery before beginning extremely strenuous activity.

Thank you for your question.  Congratulations on taking an active role in your ongoing health.  Unfortunately, a significant weight loss is likely to have some impact on the appearance of your breasts especially since your implants are very large.  They may also impact your ability to do some exercises comfortably.  Having said that, it is still a good idea to get to your ideal weight.  You will have to address the limitations and consequences of having large implants as they arise.  Best wishes.

I am going to change the question a little.  where did you get the1150 cc implants. I would have some larger reconstruction  patients for whom they would be useful?