I think you're chasing your tail thinking the camshaft is causing the vibration. Sounds like you have an engine balance problem. I don't know who welded that weight on the convertor, but it looks wrong to me. They balance convertors on the sides behind the ring gear, not on the back next to the drain plug. It's normal to see weights welded on there, but I've never heard of a regular non-offset balanced dampner being used
with an off-set balanced convertor with weights by the drain plug. I don't know where you got this convertor, or if somebody just erroneously installed it in the car before you bought it. Never assume the guy you bought it from knew what he was doing. He could have been retarded. Have you always had this vibration problem with this convertor, or did it suddenly start vibrating one day? That's really vital information to diagnosing it's cause. I never thought to ask you. A vibration could even be caused by a missing dowel pin in the back of the block that lines up the tranny to the motor.
As for low compression in just one cylinder, that is likely an unrelated problem. Exactly how
low is
low? Like 25-30 lbs? Try squirting some oil in that one cylinder and see if the compression improves. That would indicate it's the piston rings. If oil makes no difference, it's a valve or a gasket or maybe a cracked piston.
