Pulsating vibration while cruising??

I know that my converter is missing the external balance weight, but didn't think it would matter this much. Do you know where i can get these weights and where to mount them on the converter?

If you call up an old tranny shop they might set you up. I got a new TC with weights already on after I rebuilt my 360. Previous owner used TC off the 318 when he swapped in the first 360