I will soon be trying to start up a 87 Gt that has been sitting for a little over 25 years. Nothing was wrong with the car when parked and the only mod done to it was a flow master exhaust. I plan on doing a synthetic high mileage oil change with marvel mystery oil, oil filter, new gas with bottle of fuel system cleaner, new battery. Any tips or thoughts on what should be done to get it to proper operating condition again? Thanks!