They look better in my opinion with the Shelby dimensions, but I'm old fashioned when it comes to Mustangs in most regards. I've seen many a car with dual 10-inch stripes and the 2-inch gap (standard) which look like crap when seen next to the ones using the original Shelby tapered stripes. Glad to see you went to the extra effort and expense do "do it right".
2" gap. Shop around, I found a shop that has the latest and greatest laser guided system. It's not just for stripes, it's actually for whole body panels to make sure they are straight, but they lay a laser down and paint according to it. As you can see, it worked wonders on my car. Next it goes in for painted calipers and Rousch louvers.