mitchell says 3 hours to do the job figure 300 bucks(most shop rates are 80-90 dollars an hour) labor plus parts for the job, you may have a hard time finding a place that wants to mess with it since its already torn apart.....
does it just need the opti spark or does it need plugs and wires too? it adds some time to change the plugs they are in kind of a tight spot to get to