Whenever I get a clunk up front I always check the following (I've had just about every one of these places cause it over the years)..
Ball joints (with tire in the air, grab at the 6 and 12 o-clock position and wiggle, should be virtually no movement)
Wheel Bearing (with tire in air, grab tire at opposide sides.. should have virtually no play.. play at 12 & 6 only is ball joint, play at 3 and 9 only is steering components (tie rods etc).. play in all directions is bearing, or loose tire.
Shock mount (I've broken the lower one a few times)
Radius Arm Bushings (pull the bolt off the arm, remove the rear bushing and see how bad it looks)..
Those are the spots I check first. You can also check your sway bar and make sure the bushing is still there (we don't have sway bars on our truck so I don't check that)..
Those are the things I would check first...
~Mark
