Asking for a friend,He has installed a rebuilt 727 and rebuilt torque converter behind his 340 which is in a 69 Dart.He has a vibration when revving in park and when driving on freeway speeds. Could this problem be the rebuilt torque converter not balance correctly. Any input would be greatly appreciated Thank you Rick
And the wildcard is just because the 340 is in a 69 may not mean it is a 69. and even if it was a 69 it doesn't mean 50 years later that the guts are still 69 spec.
So as already mentioned, go back to the last known smooth-running combo and check the balance of that TC; compared to the current one.
Good luck
