What is the name of the part that the water pump mounts to

What is your question?

Went to replace waterpump and there is a part that it bolts to. It is where the crank shift pulley mounts to as well mine is cracked behind the waterpump. What is the name of the part so I can buy a new or used one

What makes this problem better or worse?

Won't run without it

How long has your 2006 Chevrolet Impala had this problem?

Since I bought the car