This is onlyan interesting story, but in 1975 My brother rented a 75 Cordoba for a week in Phoenix, and when he went to check the oil at the station the air cleaner said 340.
and, in the late 80's I also owned a 74 charger 440 magnum with a forged crank. 71 block, but it was a numbers matching car. So Chrysler did try to use up many of the leftover parts they had during the time period.
But, I haven't heard of someone able to order a 340 in a sedan. they could though order everything else that a 340 car came with.