UPDATE..
installed today Ngk ruthenium spark plugs older plugs came out were Motorcraft platinium and were badly worn out at 100,000 miles I'm attaching pics.. I decided to clean throttle body Complete removed with new gasket fitted and changed also PCV valve. Thoroughly cleaned intake with break cleaner and all removed parts clean assembled car ran perfect. I noticed improved in mileage on display but nothing special in throttle response or may be slightly responsive.