FYI,
I ran 275/60-15s on 8.5s on my barracuda at 24/26 and still ran the centers off.
IMO then, 8s are a lil narrow for 275/60-15s on the street. At 30 psi you'll blow the center treads off them in no time. They'll probably need to go down below 26psi to wear evenly from side to side. If you...