Old, tired 911 Porsche motors tend to leak oil. There are a lot of different reasons. This is one example, on a magnesium chain box, of something that we can do to minimize the chances of an oil weep or leak during a rebuild. Instead of sending the chain box out to a machine shop, here is a simple way to make sure your sealing surface is nice, flat and fresh to allow the gasket to do its' job properly.
As always, let us know if you have any questions. 321-806-8664