Odd question about Dusters

The 1970-71 Duster's are Identical except for the Rallye dash and grille in the 340 car. In 72 they changed the tail lights and had bumper jack slots in the bumpers,this was introduced in some late 71 cars.Also the 72 340 cars had no rallye dash,but would still have the shark tooth grille as 71's did. 1973 was a big change with the dash,front nose/grille and rear tail panel/lights.Interior door panels and handels are different as well.For the most part the body was the same.