Ocr chemistry a

Hi all I was wondering what raw mark would I need to get, if the average grade boundaries over the years are:
F321: A=48 B=42 C= 37
F322: A=70 B=62 C= 55

I want to be safely in the grade and not right on the boundary as they can move down.

I think I got approx between 35-45 marks for F321 and an A/B on the practical (F323).
Many thanks