Harmonic Balancers

I have a CAT fluid style. Thing is a tank. must weigh 50% more than a stocker but its chrome! :-) it worked with my 340 but the alignment is fubar, and fit is tight, like heat it up to install it tight. I understand it has to be to fully absorb the frequencies its designed to supress. I ended up using the outside pulley of a double pulley alternator and shimming the water pump pulley out 1/4 inch. The newer ones have a recessed pulley mount. MY original FluiDamper (real one) had the same alignment problems...that was while ago. Im thinking the dynamic style (rattler, fluid, floating inertia ring) is more suited for endurance racing and it trickled down to street.