My version of the right side Z Axis. Another members did not quite aligned the rod with the holes on my printer version (bought 03/2015). I've included the 123D file so you can make any adjustments if needed. I would suggest buying a digital caliper to make an accurate measurement mine cost around £13 from ebay. The trick with this end piece is not to push both rods right to the end. Instead make sure both long Z axis bolts are straight then align each brass thread with the bolts keeping them straight. Just tap (with a hammer) the right end piece until in the correct position.