[b1lk1]

Hello all. I am trying to help out a customer who has a car that had a 5spd T-5 conversion and it has a horrible vibration starting around 1300-1500 RPM. Poor guy paid someone $4500 CAD to get this done and cannot drive the car for fear of it self destructing. I feel that it has the wrong flywheel installed. A quick search in this section says that a 28oz flywheel must be used with a 289 engine.

I looked at the receipt given to this guy and there are no part numbers or identifying labels, just descriptions and prices. Any tips/suggestions as to what to check in order to figure out what flywheel it has without completely tearing it down? I realize I am most likely changing the flywheel anyways at this point, just want to be certain I did not miss any other possibilities first.

PS: I am sure it is using the original 289 harmonic balancer and all accessories, the only unknown is from the flywheel back. Car has not been used in this condition so it is still repairable if my suspicion is correct.

[Calponycarsmike]

If he used the late model Flywheel it would be a 50oz weight, you can try changing to a conversion Harmonic balancer they make them with a 50oz weight and the correct pattern for the early pulley but you are looking at about $160 to see if that is the issue.

http://www.calponycars.com/prodDetail.php?prodId=162

[b1lk1]

How do I tell which flywheel is in the car already?

[gtss]

if you have access to a 5.0L you could swap the balancer and run for a short period with no belts to verify the solution. just dont run it too long or it could overheat

more improtantly, how long have you lived in Acton,
I went to elementary school there....small world
gtss

[kevink1955]

I do not think you can just swap the balancer to check or correct this problem. The internal balance of the early engine is not the same as the late 50oz engine