i just bought a 83 Gt 5.0 with 5 spd. the harmonic balancer is bad so i purchased a new one and was told that any 5.0 from 83 to 95 use the same harmonic balancer. i put new one on and after a about 30 minutes of idling i noticed a lot of vibration and it got worse. i took harmonic balancer off and its key hole was worn just like the old replaced one. so i need to know from the experts out there, was i told wrong about the harmonic balancer or what?

 

don't know what you mean by worn key hole...if what to mean is you could rock it back and forth on the crank then I understand......the harmonic balancer should all be the same and are 50 ounce balancers

 

ok, thanks I just came back from shop and we measured some used balancers off of many fox body cars and they were all the same, so i probably have a bad crankshaft....when i put the new balancer on it went on way too easy which should have been a clue.....