1989 chevy p/u have had major squeaks and has tires changed twice new shock absorbers ?

i have bought a 1989 chevy p/u. when i first bought it had LT 265/75/r16 now the new used sets were not the LT"S so since then i have had major bouncing , squeaks and it is coming from the front end area on the left side (the drivers) SIDE. it is driving me crazy an hoping someone can suggest some idea to resolve this i have put new shock absorbers on too..