Yep! Just like a couple people told me, my engine runs MUCH SMOOTHER now with the "new" harmonic balancer! Mine was coming apart. The rear pulley was wobbling. I could hear a little FAN-BELT noise that NEVER WENT AWAY! Not even if the belts were replaced AND a new A/C tensioner. So folks if YOUR old Z makes endless fanbelt noise take a close look at the lower pulley. I used a remote starter while the coil wire was off. I could see that the inner pulley was moving on an eccentric orbit. It felt just a little loose. When I removed it yeserday I could see chunks of rubber missing out of the back of it! I was doing 90 on the 105frwy today and there was a guy in a nice red CAMERO racing me...oops! O.K. he was busy sneezing when I looked. Well it's nice to be back on the track!