Can you be more specific about the symptoms?

Does the engine idle at the proper idle speed, and is the speed steady or does it vary?

Does "shake" mean just a vabration or does is literally SHAKE the car?

Is the vibration frequency constant or variable?

The ignition timing @ idle speed is listed on the emission/tuneup decal on the radiator upper support.

Where did you get those valve timing specs? Mercedes valve timing specs are typically quoted at 1 mm lift, so exhaust valve closing BTC and inlet valve opening ATC is typical since the OE cams have little overlap.

Duke