Yes, mine does it in park or nuetral.Mine has all new mounts.They were poly motor and trans mount.First I switched back to rubber on motor mounts, but no change.Switched back to rubber trans mount and that hides alot of vibration.I can't find anything rubbing or touching.Trans has clearance, as does exhaust.Mopar Tech is baffled too, and does not think it is internal with the motor.He has 6 years with MP and has never seen one of these crate motors have a balance issue.He said although it is harmonic in nature, it could be a couple of cylinders being too lean, and that I should check the plugs for that, as well as anything spark related.Everything is new, and installed with motor other than the plug wires and accessories.I removed accessories belts and ran it for a minute, but it didn't help.I guess I could try another set of wires.Just seems strange that it's harmonic.If it did it all the time I could see it being spark related.