Question, I just put new tires on the rear. Went a lil bigger from 225/55 16 to 225/60 16 and since I put the tires on I notice the rear end feeling like it is" floating" now. Any thoughts as what it could be.

 

Oh it's a 92 with 8.8 in the rear

 

Upper and lower control arms are usually the cause of the rear end swaying. U could change all 4 arms pretty cheap and easy to some aluminum tubular arms and that will help considerably!! Ride will be a lot stiffer w better traction

 

Cheap tires? Put cheap tires on my beater last year and had same problem the tires were too hard almost plastic like once I wore them in it went away.

 

higher sidewall means more tire roll in a turn. Are the tires a different brand? Different type? Different tread? It's not a big difference between 55 and 60, but if the sidewalls are made differently (i.e., the new ones are softer), you're going to experience the back wheels pushing over more.