The factory piston rings do not need to be regapped, and you would not necessarily need a new head gasket or studs. That being said, the 2004-2008 trucks are getting up there in age and mileage, so we do recommend giving your truck a good once-over and making sure it's up to date on all its maintenance and TSBs. The only you may need to do post-install to ensure smooth operation is to get new plugs and gap them down tighter than stock to prevent blow-out.