Mustang Rear end project

Hi every one.
I have a 86 Mustang coupe.
I want to narrow the rear end. Was looking at the kit from S & W race cars but was wondering if any one knows of another way.
Home projects? I want it to be a do it yourself project if possible.

Thanks

I done 3 older model camaro's and a 72 nova before. Never did a mustang. So it's not my first time tubbing out a car.

The car will be drag only. No street machine., Got to get enough rubber under the car so it will bite.