So....it is an EV2 340 "promo" car. For whatever reason these cars weren't coded for the SHAKER hood, last minute change? Not surprisingly that '71 Challengers such as your car exist. Is it because of the cars "promo" status ("M" - VON?) that it doesn't have "N96" on the fender tag, as is the case for most of the "promo" GY3 440-6bbl '71 'Cudas (SHAKER & no "N96")?
I'm not familiar with EV2 340 "promo" cars? Mine does not have an M in the VON it's a Canadian car and has a B.