1971 340 LH23 vin ?
From what I've just read, L would be a Dart or Demon so that rules out the Duster. H is High value so I'm guessing it was somewhat equiped. 23 we all know is 2 door hard top. H is the 340 and 1. Is the yeAR 1971. I'm thinking this came from a 71 Demon.