Yep, Chevelle. The previous owner did this to my 71.Chevelles of this era had the sharp inside corners.
I know you're talking about the front stripes, but their rear spoiler measurements for a 73 Z28 are incorrect. They say 5/8" from the bottom of the spoiler to the bottom of the pinstripe. The assembly manual has 1".We used a stencil from Stencil's & Stripes. They are to factory specs.