Crank balancer and pulley weight.
I was in the process of replacing my tired 71 360 balancer with an aftermarket balancer and swapping pulleys from the heavy double to a lighter single. I weighed them with my fish scale. There is approximately a 3.5lb difference. I consider this a significant weight savings off the crank and added bonus of the front of the car not that it matters on a street car. I can’t believe it was that much.
I was in the process of replacing my tired 71 360 balancer with an aftermarket balancer and swapping pulleys from the heavy double to a lighter single. I weighed them with my fish scale. There is approximately a 3.5lb difference. I consider this a significant weight savings off the crank and added bonus of the front of the car not that it matters on a street car. I can’t believe it was that much.