I think what he's trying to say is that there were only two years that were factory big-block available.
Base Barracudas and Cuda's share most trim items with the exception of "performance" related options...shaker hoods, etc. As he said, on the VIN Cuda's are BS cars and Barracudas are BH cars.
Year to year:
1970 - Single headlights, thin divider in center of grille, horizontal bar across center of grille and the aforementioned inset blinkers. In the rear, it will have the square-ish tail lights with the reverse light in the same bezel as the blinkers.
1971 - Four headlights and cheese grater grille. Similar rear tail lights except that the reverse light is in a separate bezel opening.
1972, 73, 74 - Single headlights, wider divider in center of grille, turn signals moved to lower valance. Four round tail lights. Harder to differentiate between years. 72 and 73 cars had 340 available. 360 in 74. Look for bumper guards and stripe packages to help identify.
Look at eBay and Craigslist for pictures of the above details. It sounds confusing until you see a couple side-by-side, then it will become pretty obvious.
