a518 Vibration

Usually when an engine is balanced at the machine shop they balance the damper with it. So removing the damper may not be what you want to do. If you put a 400 torque converter on it I believe that may be the issue.

Because they couldn't have balance the converter with it . The only thing you can do is install a neutral balance converter. Or remove the weight from yours. The problem with removing the weight from your is what if that is not it.

We had the same issue but cured it on a run stand with a neutral balance flywheel. Then we knew it needed a neutral balance converter.

My son noticed that only the rear of the crank had heavy metal when he freshened it. He said at that time something didn't look right because there was no metal at the front. That was due to the external balance damper being used. We tried a neutral balance damper just to be sure and it vibrated.

Now when you look at the motor it looks like and externally balanced motor with that damper. But it is not. A common problem when you take a motor to the machine shop with the factory damper. When ever we do an externally balance motor here it gets a neutral balanced damper. This way the customer can use any performance damper he choses.

There is a 400 warranty block here that states it for a replacement for 71 383 4spd. on the crate. It has a forged crank and is new from chrysler. It belongs to member 1969383valiant we are wondering what that would balance at. We sold it to him in the crate. My son will check its balance status. Its getting a total tear down for new rods and pistons. . Dave is going to put it in his Valiant with aluminum heads big cam and a compression upgrade.