As tweaked as the Camaro & Mustang bodies are, a Challenger could be similarly modified to narrow it and flush the grille.
NHRA says the noses "follow production shapes", but there's no way; seems like the loophole is that the manufacturers supply the templates and NHRA accepts a pretty loose interpretation. Just look at the fascia, hoods, fenders & quarter panels: if they weren't carbureted V8s on gas with a stick, they'd pretty much be ProMods.