No the cams were the same. Only two camshafts where used on the 340 since it's intro in '68. In '68 the 4 speed cars did have a different cam grind than the auto..'69 and on, ALL 340's used the '68 auto camshaft. The '72 340's had the '360' intake valves and 8.5 CR from the lowering of the piston .100 in the bore. The '72 and the '73 340 used the very good TQ and the TQ manifold from the '71 340. Compression ratio and the intake valves were the changes from '71 to '72..and the cast crank later in the '72 model year same for the '73. My '72 Duster 340 does indeed have the forged crankshaft. JMHO..I believe the '71 340 to be THE best year for the 'mighty lightweight' ! still had the forged crank, still had the compression , still had the big valves and the TQ carb and manifold which was superior to the AFB carb/manifold. I believe it to be about 10 horse better than the '70 six-pac 340's. NHRA agreed with me,.. when they refactored the '71 340 to 330 horse. IIRC, the '68 and '70 340 was NHRA factored to 310 and the six-pac 340 to 320 horse. The '72 340 was SAE rated at 240 horse but that was a different rating system than the earlier engines received. The '72-'73's would be in the 270-275 horse range if rated at the crank. For the '68-'71 the 275 horse rating was a JOKE...We all know that Mother Mopar did infact 'underate' the '68 - '71 340 at 275. So did the NHRA..and the Insurance company's. LOL.