only made these cars for 4 yrs,,any year is desirable ,,72 to 74 e body is still better than a chevy or ford of the same year,,I love the 70 model challenger but the 72 to 74 still is better than a 71 ,,as far as the bb engines yea that was the last year they came out, which is more desirable to some but just dont care,,I could put a 383 or 440 or hemi in mine but to tell ya the truth the 340 is great,,in another 10yrs wait an see the 72 to 74 go up in collectablely and scorch the rivals ,,the fenders , doors an quarters all interchange,,grills an tails differ,,thats like saying a blond has a better smile untill bent over an becomes a readhead ,,truthfully it all feels the same when you stick it in high gear