The first 300 I touched, had a Loose front crank pulley and bolt.. it was a bit of a mess.. it all really needed to be replaced.. I ended up being able to get all the surfaces cleaned and covered with JB Weld.. I got the Bolt to tighten and hold it all the bits together till the JB Weld set up..
That engine lasted another few years in that chassis.. and the engine ended up in another car.. no issues were ever reported back..
I would guess getting the front pulley off might be a chore to do the Timing Belt replacement.. Night need some heat :) ..