A833 Vibration Issue

if it is the correct balancer and flywheel, look into the pressure plate. They sometimes throw weights if they are balanced or are just not properly balanced. Mine would shudder the whole car and rattle the dash revving in neutral. I wonder if there is a listing of part numbers for the year and engine. etc. for the crank balancer and flywheel. I am not 100% sure but if it is an external vs internal balance, I would think thepressure plate wouldnt bolt up from one to the other, maybe someone can clarify. ususally the bolt holes are offset,so you could have the correct pressure plate but it is defective as in missing a counterweight etc.

On another note, this is why I keep a 318 lying around as a spare engine,it is same balance as my 340, and save for the motor mount brackets (ears) it is a direct swap. If going 340 to 360 yo need the different balancers/flywheel /Torque converter etc.