I am looking at buying goodyear 28x9.0-15's drag slicks, and i'm wondering if i'll have any clearance problems. My rear suspension is stock, but I do plan on doing a 1" lift. Any advice? How much backspacing will i need?

If you're going to bother, I'd go at least 10.5" wide. At worst, a 28x10.5x15 might require some hammering depending on the wheels. I fit a set of 28x12.5x15 tires in mine once, but those require hammering/trimming. With the 10.5's you could use a 15x8 wheel on either a 4.5" or 5.5" backspace. The 5.5" will have the tires well under the fender, but would require some inner fender clearancing. The 4.5" backspace will have the tread just under the outer fender lip; the sidewall kind of bubbling out of the wheel well, but little to no clearancing needed. With anything 28" tall it could rub from tire growth at high speed, so look for that the first couple times.