This is where I bought mine
http://www.brothersperformance.com/
Now with an 89, you will see a little more tire rub than a 91-93 car would. I would not worry about it because I still see a little bit of rub. I got 274-40-17 on the rear and 245-40-17 on the front. You could go a little smaller in the front if you are worried about it.