Front End Looseness on High Mile Stang, What Do I Do?

Jack it up and give everything a shake and a look. Theres alot of bushings in the front end that could get wore out. I bet its a bushing of some kind.

several things come to mind. ball joints will make a clunk as they are worn. when going over a bump, they load and unload, causing a clunk. jack up the front, use jack stands, etc. grab wheel at 12 and 6 o'clock and push pull the wheel/tire. if you get some movement, suggests ball joint.
if there is movement, do same at 3 and 9 o'clock. if there is movement, tighten the not for the wheel bearings and or replace them. once tight at 3 and 9, now recheck the 12 and 6 test. if loose, bad ball joints. not hard to do.

control arm bushings can cause some clunk if really bad. visual inspection.

the bushing in the top of the strut can cause clunking for same reason for reason as ball joint.

these are the biggies that come to mind. good luck.