Rack Damper Install

[reinventthewheel]

I've got a bad idle shake that is much worse when the engine is hot (like just getting off the highway) than on a cold start.
It's an 82 300sd so it has the old damper bolt.

It's got good compression, just did a diesel purge, haven't done a valve adjustment or changed the motor mounts yet.

I found a brand new bolt for pretty cheap and I'd like to just swap out the old one as I think it will solve the problem.
However some folks suggest changing the motor mounts and doing a valve adjustment before changing the damper bolt.

Why is this?
I can't imagine anything going wrong except tightening it too much and having a hard problem with cold starts...

The damper bolt is half the price of changing the motor mounts and engine shock, the rubber on the mounts seem to be in good enough shape (not gooey or cracking). I'd rather replace the damper bolt now and do the mounts later on than end up having to do both right away.
I do plan on doing a valve adjustment, but don't see why that would really change the picture.