340 engine mount bolts torque??
If you can't do anything else, just size the bolt and look up bolt torque which is all over the internet. AKA a 3/8 grade 5 bolt is XX torque pretty much, or at least you will be safe.
Are you SURE it's not in the service manuals? Of course we have no idea what you are working on, here, so.................................................................................................................................................................
Look in section 9, "engine" NOT under the torque/ tightening specs in the back, but rather in the text where they are diagramming the engine mounts. EG the 72 book page 9-27 +/-