Will a 450 cc look too big on b cup. I am 5.4 and weight 160 pounds.

Hello and thank you for your question.  The
best advice you can receive is from an in-person consultation.  It would be helpful to know your individual breast measurements in order to give you accurate advice about implant size selection.  The size, profile, and shape of the
implant is based on your desired breast size/shape, your chest wall
measurements, and soft tissue quality.  This decision should
be based on a detailed discussion with equal input from both you
and your surgeon.   Make sure you specifically look
at before and after pictures of real patients who have had this surgery
performed by your surgeon and evaluate their results.   The most
important aspect is to find a surgeon you are comfortable with. I recommend
that you seek consultation with a qualified board-certified plastic surgeon who
can evaluate you in person.
Best wishes and good luck.
Richard G. Reish, M.D.
Harvard-trained plastic surgeon

It's hard to determine size without examining you but based on your height and weight I think the volume could be appropriate.  I recommend seeing a plastic surgeon for consultation to help pick a size.