426 hemi vibration problem

[72 cuda]

I need some advise
Just installed a 68 block 426 hemi into my 72 cuda. Engine was totally rebuild from ground up and installed by a friend of mine. The engine was machined by a shop that went bankrupt while my engine was in the shop. It took almost a year to get it back and had to be put together by another shop. It starts first shot every time but vibrates like crazy at idle and when accelerated. I do not drive it for fear of damage. I have a feeling that the harmonic balancer ( vibration damper ) is incorrect. Any ideas? and how can I tell if the one on the car is the correct one in the first place. Any help would be much appreciated. The number on the damper is 1604 2.

 

[classiccarsplus]

if you have the coolant fan bolted on already, I would take that off first. you may have a fan blade out of balance, and the motor will literally rock the body. I would then go after the flywheel or torque converter and dampner.

 

[72 cuda]

I thougt at first it might be the torque converter so I replaced it as well as the flywheel. The problem was still there. I will try the removing the fan but if that doesn't work I am guessing that it must be the damper. Just an expensive part to replace if it doesn't fix the problem
Thanks

 

[classiccarsplus]

426 hemi vibration

[ Just an expensive part to replace if it doesn't fix the problem]

don't put another fan on it right away. you can run the engine for a few minutes without a fan just to try it out. there are a couple places that restore/rebalance cooling fans, otherwise I have some for sale on my site if that is the problem. http://www.classiccarsplus.com