Plum Formula

I thought I and the original owners of my low-mile Lt-1 Formula had done a great job of caring for and maintaining my Bird but just had at least one head gasket blow after some “spirited driving”. Love this car and want it fixed correctly but I’m getting too old to do the work myself. Can anyone recommend a reputable repair shop within an hour of Merced CA??? Can GM dealers still handle this kind of work?? (…and for less than $4000???) Thanks for any help you can provide.