316 Aus SS is not an official designation for anything.
I will presume that you mean S31600 which is commonly called 316 in its wrought form.
A351 CR3M is a cast grade designation and the chemistries will be slightly different.
Since you didn't refer to a specification for the wrought material we don't know what mechanical properties you have in mind.
In general the cast materials are slightly less ductile and (depending on HT) less corrosion resistant.