312 Y Block cam counter weight is it needed?????

[Ziffer]

Started the build up on my wife's 312 today and the rebuild manual shows a counter weight to balance out the eccentric for the fuel pump. I went back to the tear down pics and it was not in the pics. I know the motor had had much mischief done to it so did someone else leave the counter weight out? I had a 62 parts motor and opened up the front end and there was not counter weight in that either. Do I need the counter weight?


Thanks in advance for assistance.
Z