Ford grew the Mustang for 1971 specifically to fit a 429 big-block, but this particular convertible — a military heritage tribute built by Impatient Creations — fills that extra room with a modern supercharged 4.6-liter V8 instead. A full 2006 Shelby Mustang interior and custom airbrush work replace the period-correct big-block approach entirely, turning the car into a deeply personal build rather than a numbers-matching restoration. Read on to find out how the so-called ‘big Mustang’ era became such a capable canvas for a tribute like this one.