My new 383 has been giving quite a bit of vibrations in the car. It is a vibration that gets fairly intense at around 2000 RPMs, but is there, albeit relatively less, at other RPMs too. When we looked at the harmonic balancer, we realized that the hub is not lining up with the 12 o'clock position as the manual says it should, but instead lines up at around the 10 o'clock position. I am thinking this is the reason for the vibrations, but wanted to ask you guys for your opinions. Thanks in advance.

 

Who's dampener? I assume the dampener is zero balanced and if so, it shouldn't matter where it lines up.

 

Well, the harmonic balancer bolts up to the balancer hub... However, it is the balancer hub is currently at the 10 o'clock position when piston #1 is at TDC, when the manual that we have says that it should be at 12 o'clock. Therefore, the harmonic balancer is pointing in the 10 o'clock position as well since it is bolted to the hub. I was wondering if this could be the cause of the vibrations. Thanks.

 

Probably not, but if you suspect it you mightbe able to take it in to a machine shop and see if they could check it for neutral balance.

Did you have your engine internally balanced? If you did, then you need to have a flywheel or flexplate that is neutrally balanced. The stock one has a counter weight on it. And vice-versa if you have a externally balanced 383 with the wrong flywheel/flexplate.