Can anyone help? What is the best way to support an off centered stacked cake if all the tiers are the same size. I plan to stack 5 8 inch tiers.

Be sure there is a balanced, center of gravity ..... then just dowel and stack as you would any other cake except they are kinda off center. If the cakes are going to overhang the edge by any significant amount, I'd use plates or other super-firm/solid support.