[FC] top cover

[Chris & Bill Strickland]

I've always thought that this recessed boss, or at least if we are 
talking about the same thing, was present on all covers -- I always 
ascribed it to an initial cranckcase vent system the was supersceded 
prior to production -- normally it is closed as cast.  Normally, the 
covers are sealed, excpt for the one vent hole, PVC or road draft..

Maybe wait for all the wags to return from convention and ask over on VV.

Bill S