340 Id

Look on the side of the block. Cast into the side is the date of production(Pass side). On the opposite side(Drivers side, last 3 or 4 didgets) there will be the displacement of that block. Anything dated from the middle of the year could have ended up in the following year car. The early months should have ended up in that years cars. Let us know what you find. Is the motor still in the car? If so is there a washer welded to the front of the K frame of that car? What does the fender tag say on the bottom line, first didgets? What car is it?, if there is even a car.
Small Block