Hey Y’all, I have a 1965 mustang gt clone I just bought recently. It has a terrible vibration. If the car is parked, in drive, neutral. You can’t feel the vibration with it just idling but as soon as you hit the accelerator the whole car starts to shake. It shakes the whole car and as you eccelerate more it seems to vibrate faster.. I’ve just changed the plugs, no vacuum leaks, as well as the harmonic balancer I just swapped out for a new one. Car was restored 10 years ago she’s a beauty. But not road worthy with this vibration. She’s got a 289, automatic c4. Car is very much bone stock. Thanks so much!!!