3406b vibration

I have a 3406b 425 cat and at idle around 625rpm it vibrates bad enough that everything in the can shakes. I rebuilt the engine I replaced everything except for the crank balancer im thinking of the Pdi liquid filled anyone have on

PHP:

e? The engine has a new head with 60k on it now im thinking it should have valves adjusted. And has anyone tried the fass fuel system I've heard they take the idle vibration away to due to the old motor new fuel problems any tips would be great thanks!