The other option is to notch the fan blades so that they will clear the balancer. It is quite common to see notched fan blades. Make a template with a nice radius for the corner of the cutout and trace the shape on each blade. Then, use a die-grinder or snips to cut. Smooth the edges and paint to match......Done

"The Operation of GMC trucks is normally smooth and steady, with no loud rattling, knocking or unusual noises. A good driver will quickly become accustomed to driving a GMC truck and will get the feel of his vehicle regardless of his engineering knowledge."-TM10-1563