I had a set of 26x10 ET Drags on a set of 10-holes, they hooked fine, but as the aged you could see they were wearing more in the center.
But back to the subject at hand, yes those 28x9's will fit with ease. I've got a buddy with 28x13.5 ET Streets on his 90 GT. They just required a rolling the fender lips and "adjusting" the inner wheel well with a 15lb sledge hammer.
-Josh, aka the tireburner