how much does it cost to have focker arm put in on 1998 Chevrolet Tracker

my car make a knocking sound that is coming from the left side of the pistons. If you are looking from under the hook. It smokes when you crank it up and it is using oil also.

Asked by for the 1998 Chevrolet Tracker
focker arms are really hard to repl but ROCKER arms are much easier. seek diag to make sure of issue as that is unlikely