Camaro_Maniac63

Hey guys,

We purchased the balanced 383 stroker kit from Eagle about a year and a half ago, and put together the engine approximately a year ago. Even since the new engine was put in, the car had vibrations which were especially strong at around 2000-2500 RPM but also existed throughout the RPM range.

The engine was put back together with the stock flywheel and harmonic balancer. We thought that the LT1 was internally balanced, and assumed that since the new kit was balanced as well, stock flywheel and balancer would work OK with the new rotating assembly. However, my research lately seems to be suggesting that LT1s are internally balanced at the front and balanced by a counter-weighted flywheel at the rear, meaning that the stock flywheel is not neutral balanced. If so, this would explain the vibrations...

My question is, for those who have built 383 strokers using balanced rotating assemblies:

- Did you have to use a neutral balanced flywheel? Or did you use the stock flywheel and harmonic balancer?

Any help is appreciated, thanks in advance.

95Blackhawk

When I had mine done by the rebuilder, he said he could do external or internal so I decided upon internal. As stock, they are external with flywheel.

They took my stock flywheel and PP to neutral balance at the shop then I installed it myself. Sounds like you need to get this done. Damn shame.