The prop should stop in the 10 - 4 position when looked at from the front. Also if you look on the back of the hub,on the neck of the blade there is a #1 blade and a #2 blade. The Continental overhaul manual mentions which cylinder the #1 blade must be on. I don't have mine on hand right now. The rubber bushings are best new. most rubber nowdays have a 5 year shelf life in an air conditioned warehouse in a zip-lock baggie in a dark corner and dusted with talcum powder. Rubber made over 20 years ago should be good and dead by now. Rubber in use in the engine should be replaced about every 5 years of use. Specially if it has already spent 4.5 years on the shelf. I tell customers to chew their spare rubber parts for about an hour or two and if they still have a single piece and nothing came apart, it is good to be used. Nobody can get one of these rubber peices in the trunk of their car, much less in their mouth, but they get the idea. Next thing to look at is compression. Uneven compression will cause vibration. Just turning the prop backwards by hand eight times will do to check compressions. If one cylinder has low compression then the plot thickens... AF. N87333 N94694
