Idler Arm

On a 1968 Dodge Dart GTS is there supposed to be a spacer, thick washer, thin washer that is supposed to be installed either on top of or on the bottom of the IDLER ARM? I am changing my engine and transmission and while it is on the lift I remembered in the past hearing a clunking noise when turning the steering wheel. When missing with the steering components I seen the idler arm moving. I pulled the bolt and seen that it was worm part way through, about .080 missing on one side of the bolt. Ordered a new bolt and received it yesterday. Previously when removing the bolt I seen a thicker than normal yellow washer in the cavity where the idler arm sits. When looking up idler arms for sale on line I seen some with that have just the arm and standard rubber bushing on top and bottom but I also seen one for sale that has what looks like a yellow bushing on top. So I am confused, should there be a washer on top or bottom of the idler arm with the bolt going through it, if so what would be the proper thickness of the spacer (I can not find any information online). I know this can not be answered here but how else could that thick washer get in the cavity behind the idler arm, is it supposed to be there but perhaps fell out when installing the bolt?

*** Thanks to all those viewing and those that might view this post. I actually found my most of my answer on this forum in a post by

6pk2goDemon ... THANK YOU !!!​