1971-72 Duster Twister package.
Has nothing to do with the Twister Package which is not available on the 340, it's the V24 stripe option.
The 1972 340 Duster had a V21 option, it was the same (or it appears to be, minus the socops) as the black hood option the came on the /6-318 Twisters.
Not as cool as the 1971 V24 but could have been if the 340 callout wasn't dropped.