Suspension Question?????

I have a 1994 mustang GT. I just put a new set of 245/50/16 tread all the way around, and it seemed that soon after putting these tires on, the front drivers side lower ball joint went bad (starting sqeaking when wheels turned). So after replacing the lower ball joint I noticed that every once in a while either sitting in the drive way or at the gas station filling up, it will look like the suspension is slamed a couple of inches, but just on the drivers side and not all of the time. I have looked at the suspension multiple times and can't see any obvious defects. I was wondering if anyone has any suggestions...bad suspension, broken spring, bad ball joint? Any help would be great!!!!!
Thanks,
black94mustang

They were 225/60/16 junkers I had laying around. But I know it wasn't tire pressure or the new tires, because when I thought it didn't look right, i walked around the car and the passenger front looked fine. So I dunno?