Does the old flexplate have a weight welded to it? If it does, and it looks "factory", you need an external-balance flexplate. If it does not, and it looks "factory", you need an internal (neutral balance) flexplate.
If it has some kind of weight--or drilled holes to lighten it--and it looks like it was done after the flexplate was made, you need to haul the old flexplate and the new one to a balance shop to have them matched. Balance shops that rework the damper or flexplate are doing a poor job--but it does happen.
If it has some kind of weight--or drilled holes to lighten it--and it looks like it was done after the flexplate was made, you need to haul the old flexplate and the new one to a balance shop to have them matched. Balance shops that rework the damper or flexplate are doing a poor job--but it does happen.
