Was it like that when you first got the engine done? I would check the run out on the pinion shaft of the flywheel assembly. If it's more than about .003, I would suspect that the flywheels have shifted. That will cause a major imbalance condition.
If that is the case, the only cure is removal so that the flywheels assembly can be re-trued. At that point, you might as well have them re-balanced while you are at it as mentioned above.
The engines can be custom built or rebuilt and the crankshaft balance factor moved around so that the vibration will be greatly reduced at the rpm range you will use most.
Example, if one wants smoothness at a hiway crusing speed, a slighty higher balance factor would be used.
If one wants a full blaster, then a lower balance factor would be a better choice.
The head/piston design on these are a problem, it can be seen that the company dropped it on thier latest engines
Thanks for all your advice!! Tore engine down this week and found one of the flywheels had come loose!!!!Said the hell with it and orderd new flywheel assembly!Also the cam was on its way out!! (Hardening was coming off one of the lobes!)Time for a overhaul!