The cars are worth less, their parts are worth less, the motors assembled are worth less, so the blocks are worth less too. '71 motors (with '71 dated VINs, not with '71 cast numbers necessarily) have forged cranks and 2.02 valve J heads stock with high comp pistons. '72 and '73 motors had cast cranks, '73s had 587 instead of 915 heads, and both had 1.88 intakes. I've got a June '71 dated '72 block cast crank motor- most of the June or later motors I've seen are the next model year. The VIN pads aren't hard to find and it's a good thing to look at the pad to make sure the year it was.
