squirrely front end 1984 300d

i own a 1984 300d turbodeisel with 186k on it that i bought used a couple of years ago. since then i replaced the tie rod ends( which were bent by a tow truck ). all 4 shocks, steering dampener, new tires, and hade the front end lined up by the dealer.
however when i take the car out on the highway, i seem to have some play in the steering. it seems like the steering is to light,
kind of how it feels like when your driving on a real windy day, but with no wind. any suggestions ??
thanks