[Jerry Clayton]

I would not like to be anywhere near a flywheel with weight WELDED on to it--------

Ford engines have used two different amounts of unbalance--28 and 50 in oz----and of course that gives you the possibility of having 3 different/wrong weights on both front or rear-----

You could get a new aftermarket flywheel which can come with both the 28 and 50 in/oz wt plus of course be Zero balanced with out either --- then you can run the engine with no weight, 28, or 50 to see if this corrects the problem-------(assuming front balancer is OK)----

And I'm assuming you mean an entire car SHAKE instead of a little noisy exhaust vibration possibly coming from a loose silencer inside the side pipe---------