Alright lets see if we can get this.... You can have any shop that has tuning capabilities "hook" up.. Would I trust anyone with a 3800 engine? NO.. For now get a tune from one of the vendors and make sure you tell them exactly what you have on the car. That will be the easiest unless you get someone around you that knows these cars to help you.. Its not as easy as changing a couple things around... If you dont want to send your stock one in pay the core and then just keep your old one.......