I have owned my car for 6 years, 1972 Dodge Charger with rebuilt 1990 360 motor. 9:1 stock or small upgrade cam. Davis HEI Ignition, Holley street avenger carb. Stiff suspension and ride with heavier springs, shocks, torsion and sway bars, 18" wheels, 45 series tires. Driven 4X/week on street only, rough roads here in urban L.A. B&M Flexplate, Mopar performance 145K torque converter with neutral balance (no weight(s)). When torque converter was installed 5 years ago the shop had to knock off the weight to make converter neutral balance as B&M Flexplate is already balanced. Car ran smooth and strong for many years. 1 year ago I noticed a little vibration upon acceleration. Got progressively worse over the last year. No one else that anything unusual but I knew better. Got progressively worse until others noticed vibration and then clunking over bumps. Sure enough, tranny mount was bad but that stopped clunking, not vibration. Rebuilt carb, new plugs, verified timing, verified spark plug wire order. Car runs really strong but vibration still there. 18" vacuum at idle and needle rock solid so I cannot believe it is a tuning issue. I replaced harmonic damper with Summit Racing damper #163318 for external balance 360. My old damper looks exactly like Mopar Performance P5007301. If anything vibration may be worse. Then replaced motor mounts. Still no change. Vibration is so bad now I only drive car to take it to get opinions from expert mechanics. For sure it is engine/balancing/torque converter as vibration is there when car in park or neutral or when it is driven, hot or cold. Exact same smyptoms as Kielbasa's original vibration post only mine have developed over time. Dash, steering wheel, and floor pan shake at anything above idle, sort of smooths out on hiway but turns into a droning vibration. Front of engine and rear of car don't seem to have vibration, it is centered in rear of engine/front of tranny. Help!!! Don't know what to replace or check next. Can a torque converter go out of balance from neutral? Thinking of rebuilding original damper but now I am getting into replacing my new replacement parts...