I got a lovley 83 300sd and the engine shakes "specially with the A/C on"
The Guy said its
1-Engine mounts
and i'm thinking of changing them my self so i'll appreciate ant advise or stuff to avoid or take care of

2- Air Filter mounts
I already tried to do that but i didnt make a differance

3- Lat "RACK IDLE PIN/ON INJECTION PUMP"
AND TURBO DRAIN GROMMETS
would you please tell me what those mean and where are they in the engine
thanx