I'm pretty sure you're going to have to do a little modifying to clear with a drop. My 79 pace car didn't clear with factory stance. I just had to do a little massaging of the inner fender (rear wheels) though. I'm sure 79 is slightly different, but I also had to bend a small piece up on the inside of upper/outer wheel arch lips. I'm not sure what it's for, but my 88gt and 86 coupe don't have them. They were just small flimsy clips attached to the inside. I folded them up with a small hammer. Most people either have to roll the fenders, or massage the inner opening when they lower these cars and go up in tire size. It depends on the wheel offset, brand/style of tire, rear control arm/ suspension setup, and a few other things. Occasionally, I'll hear of someone clearing larger tires with a drop without having to modify anything, but it's pretty rare.