Yards in SD are reluctant to have much work done in them by owners due to the possibilty of running afoul of
California EPA laws. (Of which we have too many). Best bet is probably Kohler Kraft to do your own work.
Another idea is to take the 60 mile trip south to
Baja Naval and get things done cheaper, work on it yourself, avoid the huge layday charges SD has. Only a 75 minute drive by car.