New brake rotor lateral runout problem
 

Installing new 930 rear rotors and checked the lateral runout, found .77mm on right rear and .46mm on left rear. Specs call for .05mm. Put a pair of standard new rear rotors on to check and found they were at .06mm or less. What gives with the new Zimmerman Rotors?

Problem solved. Nothing wrong with the Zimmerman Rotors. Here's the story and it might help others. I am doing a 930 brake conversion on my 72. Purchased a 930 brake kit from Jeff Gamroth, everything needed in the kit and it's beautiful. After installing the rears I noticed the deep six seem to have a lateral wobble when I spun it. Tried the other wheels, same thing. Checked the rotor and found a .77mm runout on the right, .46mm on the left. Removed the 930 rotors and put the original rotors and found .06 or less. WTF. I started looking/checking at everything. Axle stub, wheel hub, all perfect. I tried installing the 930 rotor without the small 6mm countersunk screws and noticed that the runout was much less, like .25mm less. What I found was the inner ID of the 930 rotor where it mates to the wheel hub had a smaller ID than the OD of the wheel hub. Not by much but enough to cause interference when torquing down. I removed about .5mm of the OD on the wheel hub and everything fits perfect.
Just some information that may help others.

did you use a lathe?

Yes I did.