To do it stock the body would have to be different (since the way the side trim attaches), the bumpers, grille, headlights, suspension, wheels, tires...at least 50% of the kit would be different. It's an unusual kit, an '80-84 Coupe de Ville w/ '90-92 Brougham trim...such cars do exist in 1:1, built as custom lowriders.
I'd love to see either a stock Coupe de Ville or Brougham kitted, but am not holding my breath..(neither the CdV or Brougham pictured below has the stock grille).