I was digging into this years ago.
The advise I received: piece of string from the flange at the gear box to the flange in the differential.
Caution about the hood being damaged if rear mount is set too low.
Good checkpoint is valve cover removal - if you have issues, because of the firewall, you are too low.
Tightening needs to happen after some rocking of the car, on the car standing on its wheels (in case you need to losen some components there).