Decode 440 block

3-3-72 is totally possible for any motor. And as for the assembly date of 6-30, it could be either, although if the 3-3 casting date is correct it would not be 6-30-71. Also, a 6-30 assembly date would be verrrry late in the model year but could still be installed in a late build car. The "H" makes the engine a 72 motor!! Geof