Narrowing the rear is way out of my pay grade and idk even where to go for that. But Im in NY so it shouldn't be all that hard to find someone. Here's the thing, I have 391's now, and was thinking of switching them out for more user friendly highway driving but I'm not sure yet. If I were to narrow the rear, in order not to have to lift the car in back as much to fit the tires I want, and chose to switch the gears later, would that effect the narrowing I just did ? If I went that route, I could probably just rebuild the springs with slightly more height and almost go with stock shocks. The car has air shocks now from the previous owner and I want this out asap.