waterbury time only movement question

I recently purchased a time only movement on E bay and the plate is stamped with 6 1/2..is this a number for pendulum length??

Hi Mark,

I am not exactly sure of the" EXACT" answer to your question, but it is related to the length of the pendulum. It may be from where the suspension spring is attached to the clock movement or from the canon tube for the hour hand. I have been hoping someone would come up with the "CORRECT" answer. But your on the right track.
Sorry to keep you waiting so long for a reply.

MARK, WHAT YOU NEED TO DO IS PUT A SUSPENSION AND A PENDULUM ON YOUR MOVEMENT AND ALSO PUT THE HANDS ON HANG IT ON THE WALL AND LET IT RUN 3OR4 DAYS TO TEST IT. START BY MEASUREING FROM THE BOTTOM OF THE SUSPENSION POST TO THE BOTTOM OF THE PENDULUM DO THAT FIRST BECAUSE IT WILL BE YOUR LONGEST DIMENSION IF YOU FIND THAT TO BE INCORRECT MEASURE FROM THE HOUR PIPE TO THE BOTTOM OF THE PENDULUM. I HAVE SEEN THINGS STAMPED ON AMERICAN MOVEMENTS THAT HAD NOTHING TO DO WITH PENDULUM DROP. I HAVE A LOT OF SUSPENSION MATERIAL IF YOU NEED ONE LET ME KNOW AND I WILL SEND ONE TO YOU YOU PAY THE POSTAGE. EDDIE