Pay close attention that the parts are fitted correctly as shown
In use the domed washers will touch the rubber centres as the engine carrier and body transfer loads and move up/down. This part is essentially unchanged since the 911 was launched and I've seen first hand the effects of incorrectly fitting the mounts on a 912. In this case the top washers were omitted by accident and the bolts bore directly down on the mounts centre tubes which lasted quite well until the tubes tore out of the rubber and the engine ended up on the road.
In use the domed washers will touch the rubber centres as the engine carrier and body transfer loads and move up/down. This part is essentially unchanged since the 911 was launched and I've seen first hand the effects of incorrectly fitting the mounts on a 912. In this case the top washers were omitted by accident and the bolts bore directly down on the mounts centre tubes which lasted quite well until the tubes tore out of the rubber and the engine ended up on the road.