I recently rebuilt the 700R4, new torque converter, put in a 4th Gen rear-end (with upgrades to disk/posi/gears), and complete front end suspension (along with shocks and springs for new rear) all on a 91 Camaro RS (stock...well, not anymore ). My issue is a loud noise at low speeds and increses with a violent vibration as speed increases. Dash rattles, steering wheel shakes, rear-view mirror dances and my teeth chatter when highway speeds are necessary. Is the stock steel Driveshaft the cause? Transmission mount? Torque arm? Rear-end alignment? Pan-hard Rod? What diagnostics can I do in my garage to narrow down the weak link?