Pinion shims

I'm rebuilding a '99, S10, differential with new ring and pinion. Instructions suggest using a new pinion shim that is the same thickness as the old one. With the backlash set to .008 the tooth mesh was centered top to bottom but too close to the heel. I need to move the mesh towards the toe about 20% to center the pattern.

Is there a rule of thumb for how many thousandths to add to the pinion shim to move the mesh towards the toe?

Thanks

unfortunately there is not. you will need a variety of shim thicknesses to acheive the center line of the ring gear. did the ring and pinion come with any shims?