Hey smart engine guys... can you help me?

Cerwin, block weights would fluctuate year to year, depending on the cast. The earlier 71-74 blocks would weigh more, due to the fact they have a thicker cylinder wall. Later blocks would be lighter, but also couldnt be overbored as much, the magnum block is the lightest as of now, I believe is it 155 pounds? The weight difference would be barely noticeable Im certain.